CWE - VIEW SLICE: CWE-844: Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011) (4.15)

CWE VIEW: Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)

View ID: 844

Vulnerability Mapping: PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Type: Graph

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Objective

CWE entries in this view (graph) are fully or partially eliminated by following the guidance presented in the book "The CERT Oracle Secure Coding Standard for Java" published in 2011. This view is considered obsolete as a newer version of the coding standard is available.

Audience

Stakeholder	Description
Software Developers	By following The CERT Oracle Secure Coding Standard for Java, developers will be able to fully or partially prevent the weaknesses that are identified in this view. In addition, developers can use a CWE coverage graph to determine which weaknesses are not directly addressed by the standard, which will help identify and resolve remaining gaps in training, tool acquisition, or other approaches for reducing weaknesses.
Product Customers	If a software developer claims to be following The CERT Oracle Secure Coding Standard for Java, then customers can search for the weaknesses in this view in order to formulate independent evidence of that claim.
Educators	Educators can use this view in multiple ways. For example, if there is a focus on teaching weaknesses, the educator could link them to the relevant Secure Coding Standard.

Relationships

The following graph shows the tree-like relationships between weaknesses that exist at different levels of abstraction. At the highest level, categories and pillars exist to group weaknesses. Categories (which are not technically weaknesses) are special CWE entries used to group weaknesses that share a common characteristic. Pillars are weaknesses that are described in the most abstract fashion. Below these top-level entries are weaknesses are varying levels of abstraction. Classes are still very abstract, typically independent of any specific language or technology. Base level weaknesses are used to present a more specific type of weakness. A variant is a weakness that is described at a very low level of detail, typically limited to a specific language or technology. A chain is a set of weaknesses that must be reachable consecutively in order to produce an exploitable vulnerability. While a composite is a set of weaknesses that must all be present simultaneously in order to produce an exploitable vulnerability.

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844 - Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 2 - Input Validation and Data Sanitization (IDS) - (845)

Weaknesses in this category are related to rules in the Input Validation and Data Sanitization (IDS) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.Improper Encoding or Escaping of Output - (116)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 845 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 2 - Input Validation and Data Sanitization (IDS)) > 116 (Improper Encoding or Escaping of Output)

The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.Output SanitizationOutput ValidationOutput Encoding

Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.Use of Externally-Controlled Format String - (134)

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.Improper Neutralization of Line Delimiters - (144)

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as line delimiters when they are sent to a downstream component.

The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component.

The product validates input before it is canonicalized, which prevents the product from detecting data that becomes invalid after the canonicalization step.

The product filters data in a way that causes it to be reduced or "collapsed" into an unsafe value that violates an expected security property.

The product performs authentication based on the name of a resource being accessed, or the name of the actor performing the access, but it does not properly check all possible names for that resource or actor.

The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.

The product uses a regular expression that does not sufficiently restrict the set of allowed values.

The product defines policy namespaces and makes authorization decisions based on the assumption that a URL is canonical. This can allow a non-canonical URL to bypass the authorization.

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.Shell injectionShell metacharactersOS Command Injection

The product uses or specifies an encoding when generating output to a downstream component, but the specified encoding is not the same as the encoding that is expected by the downstream component.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 3 - Declarations and Initialization (DCL) - (846)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 846 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 3 - Declarations and Initialization (DCL))

Weaknesses in this category are related to rules in the Declarations and Initialization (DCL) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 846 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 3 - Declarations and Initialization (DCL)) > 665 (Improper Initialization)

The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 4 - Expressions (EXP) - (847)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 847 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 4 - Expressions (EXP))

Weaknesses in this category are related to rules in the Expressions (EXP) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 847 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 4 - Expressions (EXP)) > 252 (Unchecked Return Value)

The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.

The product defines a signal handler that calls a non-reentrant function.

The product compares object references instead of the contents of the objects themselves, preventing it from detecting equivalent objects.

The product uses the wrong operator when comparing a string, such as using "==" when the .equals() method should be used instead.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 5 - Numeric Types and Operations (NUM) - (848)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 848 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 5 - Numeric Types and Operations (NUM))

Weaknesses in this category are related to rules in the Numeric Types and Operations (NUM) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 848 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 5 - Numeric Types and Operations (NUM)) > 197 (Numeric Truncation Error)

Truncation errors occur when a primitive is cast to a primitive of a smaller size and data is lost in the conversion.

The product divides a value by zero.

When converting from one data type to another, such as long to integer, data can be omitted or translated in a way that produces unexpected values. If the resulting values are used in a sensitive context, then dangerous behaviors may occur.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 6 - Object Orientation (OBJ) - (849)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 849 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 6 - Object Orientation (OBJ))

Weaknesses in this category are related to rules in the Object Orientation (OBJ) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 849 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 6 - Object Orientation (OBJ)) > 374 (Passing Mutable Objects to an Untrusted Method)

The product sends non-cloned mutable data as an argument to a method or function.

Sending non-cloned mutable data as a return value may result in that data being altered or deleted by the calling function.

The product compares classes by name, which can cause it to use the wrong class when multiple classes can have the same name.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 849 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 6 - Object Orientation (OBJ)) > 491 (Public cloneable() Method Without Final ('Object Hijack'))

A class has a cloneable() method that is not declared final, which allows an object to be created without calling the constructor. This can cause the object to be in an unexpected state.

Inner classes are translated into classes that are accessible at package scope and may expose code that the programmer intended to keep private to attackers.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 849 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 6 - Object Orientation (OBJ)) > 493 (Critical Public Variable Without Final Modifier)

The product has a critical public variable that is not final, which allows the variable to be modified to contain unexpected values.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 849 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 6 - Object Orientation (OBJ)) > 498 (Cloneable Class Containing Sensitive Information)

The code contains a class with sensitive data, but the class is cloneable. The data can then be accessed by cloning the class.

An object contains a public static field that is not marked final, which might allow it to be modified in unexpected ways.

The product declares an array public, final, and static, which is not sufficient to prevent the array's contents from being modified.

The product declares a critical variable, field, or member to be public when intended security policy requires it to be private.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET) - (850)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET))

Weaknesses in this category are related to rules in the Methods (MET) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET)) > 487 (Reliance on Package-level Scope)

Java packages are not inherently closed; therefore, relying on them for code security is not a good practice.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET)) > 568 (finalize() Method Without super.finalize())

The product contains a finalize() method that does not call super.finalize().

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET)) > 573 (Improper Following of Specification by Caller)

The product does not follow or incorrectly follows the specifications as required by the implementation language, environment, framework, protocol, or platform.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET)) > 581 (Object Model Violation: Just One of Equals and Hashcode Defined)

The product does not maintain equal hashcodes for equal objects.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET)) > 583 (finalize() Method Declared Public)

The product violates secure coding principles for mobile code by declaring a finalize() method public.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET)) > 586 (Explicit Call to Finalize())

The product makes an explicit call to the finalize() method from outside the finalizer.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET)) > 589 (Call to Non-ubiquitous API)

The product uses an API function that does not exist on all versions of the target platform. This could cause portability problems or inconsistencies that allow denial of service or other consequences.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 850 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 7 - Methods (MET)) > 617 (Reachable Assertion)

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.assertion failure

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR) - (851)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 851 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR))

Weaknesses in this category are related to rules in the Exceptional Behavior (ERR) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 851 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR)) > 209 (Generation of Error Message Containing Sensitive Information)

The product generates an error message that includes sensitive information about its environment, users, or associated data.

The product does not handle or incorrectly handles when a parameter, field, or argument name is specified, but the associated value is missing, i.e. it is empty, blank, or null.

The product does not handle or incorrectly handles when a value is not defined or supported for the associated parameter, field, or argument name.

An exception is thrown from a function, but it is not caught.

A J2EE application uses System.exit(), which also shuts down its container.

The product detects a specific error, but takes no actions to handle the error.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 851 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR)) > 395 (Use of NullPointerException Catch to Detect NULL Pointer Dereference)

Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer.

Throwing overly broad exceptions promotes complex error handling code that is more likely to contain security vulnerabilities.

The product does not clean up its state or incorrectly cleans up its state when an exception is thrown, leading to unexpected state or control flow.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 851 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR)) > 497 (Exposure of Sensitive System Information to an Unauthorized Control Sphere)

The product does not properly prevent sensitive system-level information from being accessed by unauthorized actors who do not have the same level of access to the underlying system as the product does.

The code has a return statement inside a finally block, which will cause any thrown exception in the try block to be discarded.

The Servlet does not catch all exceptions, which may reveal sensitive debugging information.Missing Catch Block

Chain - a Compound Element that is a sequence of two or more separate weaknesses that can be closely linked together within software. One weakness, X, can directly create the conditions that are necessary to cause another weakness, Y, to enter a vulnerable condition. When this happens, CWE refers to X as "primary" to Y, and Y is "resultant" from X. Chains can involve more than two weaknesses, and in some cases, they might have a tree-like structure.Unchecked Return Value to NULL Pointer Dereference - (690)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 851 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR)) > 690 (Unchecked Return Value to NULL Pointer Dereference)

The product does not check for an error after calling a function that can return with a NULL pointer if the function fails, which leads to a resultant NULL pointer dereference.

Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.Improper Check or Handling of Exceptional Conditions - (703)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 851 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR)) > 703 (Improper Check or Handling of Exceptional Conditions)

The product does not properly anticipate or handle exceptional conditions that rarely occur during normal operation of the product.

The product does not properly return control flow to the proper location after it has completed a task or detected an unusual condition.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 9 - Visibility and Atomicity (VNA) - (852)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 852 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 9 - Visibility and Atomicity (VNA))

Weaknesses in this category are related to rules in the Visibility and Atomicity (VNA) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 852 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 9 - Visibility and Atomicity (VNA)) > 362 (Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'))

The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.

If two threads of execution use a resource simultaneously, there exists the possibility that resources may be used while invalid, in turn making the state of execution undefined.

The product does not lock or does not correctly lock a resource when the product must have exclusive access to the resource.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 852 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 9 - Visibility and Atomicity (VNA)) > 567 (Unsynchronized Access to Shared Data in a Multithreaded Context)

The product does not properly synchronize shared data, such as static variables across threads, which can lead to undefined behavior and unpredictable data changes.

The product utilizes multiple threads or processes to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes.

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK) - (853)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 853 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK))

Weaknesses in this category are related to rules in the Locking (LCK) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 853 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK)) > 412 (Unrestricted Externally Accessible Lock)

The product properly checks for the existence of a lock, but the lock can be externally controlled or influenced by an actor that is outside of the intended sphere of control.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 853 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK)) > 413 (Improper Resource Locking)

The product does not lock or does not correctly lock a resource when the product must have exclusive access to the resource.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 853 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK)) > 609 (Double-Checked Locking)

The product uses double-checked locking to access a resource without the overhead of explicit synchronization, but the locking is insufficient.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 853 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK)) > 667 (Improper Locking)

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 853 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK)) > 820 (Missing Synchronization)

The product utilizes a shared resource in a concurrent manner but does not attempt to synchronize access to the resource.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 853 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK)) > 833 (Deadlock)

The product contains multiple threads or executable segments that are waiting for each other to release a necessary lock, resulting in deadlock.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 11 - Thread APIs (THI) - (854)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 854 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 11 - Thread APIs (THI))

Weaknesses in this category are related to rules in the Thread APIs (THI) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 854 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 11 - Thread APIs (THI)) > 572 (Call to Thread run() instead of start())

The product calls a thread's run() method instead of calling start(), which causes the code to run in the thread of the caller instead of the callee.

The product does not properly return control flow to the proper location after it has completed a task or detected an unusual condition.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 12 - Thread Pools (TPS) - (855)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 855 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 12 - Thread Pools (TPS))

Weaknesses in this category are related to rules in the Thread Pools (TPS) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 855 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 12 - Thread Pools (TPS)) > 392 (Missing Report of Error Condition)

The product encounters an error but does not provide a status code or return value to indicate that an error has occurred.

The product does not properly control situations in which an adversary can cause the product to consume or produce excessive resources without requiring the adversary to invest equivalent work or otherwise prove authorization, i.e., the adversary's influence is "asymmetric."

The product's resource pool is not large enough to handle peak demand, which allows an attacker to prevent others from accessing the resource by using a (relatively) large number of requests for resources.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 13 - Thread-Safety Miscellaneous (TSM) - (856)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 856 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 13 - Thread-Safety Miscellaneous (TSM))

Weaknesses in this category are related to rules in the Thread-Safety Miscellaneous (TSM) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO) - (857)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 857 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO))

Weaknesses in this category are related to rules in the Input Output (FIO) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 857 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)) > 135 (Incorrect Calculation of Multi-Byte String Length)

The product does not correctly calculate the length of strings that can contain wide or multi-byte characters.

The product receives input from an upstream component, but it does not account for byte ordering (e.g. big-endian and little-endian) when processing the input, causing an incorrect number or value to be used.

During installation, installed file permissions are set to allow anyone to modify those files.

While it is executing, the product sets the permissions of an object in a way that violates the intended permissions that have been specified by the user.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 857 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)) > 359 (Exposure of Private Personal Information to an Unauthorized Actor)

The product does not properly prevent a person's private, personal information from being accessed by actors who either (1) are not explicitly authorized to access the information or (2) do not have the implicit consent of the person about whom the information is collected.Privacy violationPrivacy leakPrivacy leakage

Creating and using insecure temporary files can leave application and system data vulnerable to attack.

The product does not release or incorrectly releases a resource before it is made available for re-use.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 857 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)) > 405 (Asymmetric Resource Consumption (Amplification))

The product does not properly "clean up" and remove temporary or supporting resources after they have been used.Insufficient Cleanup

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 857 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)) > 532 (Insertion of Sensitive Information into Log File)

Information written to log files can be of a sensitive nature and give valuable guidance to an attacker or expose sensitive user information.

The product constructs pathnames from user input, but it does not handle or incorrectly handles a pathname containing a Windows device name such as AUX or CON. This typically leads to denial of service or an information exposure when the application attempts to process the pathname as a regular file.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 857 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)) > 732 (Incorrect Permission Assignment for Critical Resource)

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 857 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)) > 770 (Allocation of Resources Without Limits or Throttling)

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER) - (858)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 858 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER))

Weaknesses in this category are related to rules in the Serialization (SER) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 858 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER)) > 250 (Execution with Unnecessary Privileges)

The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.

The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.Resource Exhaustion

The code contains a class with sensitive data, but the class does not explicitly deny serialization. The data can be accessed by serializing the class through another class.

The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.Marshaling, UnmarshalingPickling, UnpicklingPHP Object Injection

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 16 - Platform Security (SEC) - (859)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 859 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 16 - Platform Security (SEC))

Weaknesses in this category are related to rules in the Platform Security (SEC) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 859 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 16 - Platform Security (SEC)) > 111 (Direct Use of Unsafe JNI)

When a Java application uses the Java Native Interface (JNI) to call code written in another programming language, it can expose the application to weaknesses in that code, even if those weaknesses cannot occur in Java.

A product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor.

The elevated privilege level required to perform operations such as chroot() should be dropped immediately after the operation is performed.

The product does not adequately verify the identity of actors at both ends of a communication channel, or does not adequately ensure the integrity of the channel, in a way that allows the channel to be accessed or influenced by an actor that is not an endpoint.Adversary-in-the-Middle / AITMMan-in-the-Middle / MITMPerson-in-the-Middle / PITMMonkey-in-the-MiddleMonster-in-the-MiddleManipulator-in-the-MiddleOn-path attackInterception attack

The authentication scheme or implementation uses key data elements that are assumed to be immutable, but can be controlled or modified by the attacker.

The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

The product uses external input with reflection to select which classes or code to use, but it does not sufficiently prevent the input from selecting improper classes or code.Reflection Injection

The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

The product uses a protection mechanism that relies on the existence or values of an input, but the input can be modified by an untrusted actor in a way that bypasses the protection mechanism.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 17 - Runtime Environment (ENV) - (860)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 860 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 17 - Runtime Environment (ENV))

Weaknesses in this category are related to rules in the Runtime Environment (ENV) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 860 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 17 - Runtime Environment (ENV)) > 349 (Acceptance of Extraneous Untrusted Data With Trusted Data)

The product, when processing trusted data, accepts any untrusted data that is also included with the trusted data, treating the untrusted data as if it were trusted.

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 860 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 17 - Runtime Environment (ENV)) > 732 (Incorrect Permission Assignment for Critical Resource)

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

Category - a CWE entry that contains a set of other entries that share a common characteristic.The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC) - (861)

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 861 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC))

Weaknesses in this category are related to rules in the Miscellaneous (MSC) chapter of The CERT Oracle Secure Coding Standard for Java (2011).

844 (Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)) > 861 (The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC)) > 259 (Use of Hard-coded Password)

The product contains a hard-coded password, which it uses for its own inbound authentication or for outbound communication to external components.

The product does not encrypt sensitive or critical information before storage or transmission.

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

The lack of entropy available for, or used by, a Pseudo-Random Number Generator (PRNG) can be a stability and security threat.

True random number generators (TRNG) generally have a limited source of entropy and therefore can fail or block.

A Pseudo-Random Number Generator (PRNG) uses the same seed each time the product is initialized.

A Pseudo-Random Number Generator (PRNG) is initialized from a predictable seed, such as the process ID or system time.

The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.Memory Leak

The product uses the singleton pattern when creating a resource within a multithreaded environment.

The product contains hard-coded credentials, such as a password or cryptographic key.

Vulnerability Mapping Notes

Usage: PROHIBITED

(this CWE ID must not be used to map to real-world vulnerabilities)

Reason: View

Rationale:

This entry is a View. Views are not weaknesses and therefore inappropriate to describe the root causes of vulnerabilities.

Comments:

Use this View or other Views to search and navigate for the appropriate weakness.

Notes

Relationship

The relationships in this view were determined based on specific statements within the rules from the standard. Not all rules have direct relationships to individual weaknesses, although they likely have chaining relationships in specific circumstances.

References

[REF-813] Fred Long, Dhruv Mohindra, Robert C. Seacord, Dean F. Sutherland and David Svoboda. "The CERT Oracle Coding Standard for Java". 1st Edition. Addison-Wesley Professional. 2011-09-18.

View Metrics

	CWEs in this view		Total CWEs
Weaknesses	104	out of	939
Categories	17	out of	374
Views	0	out of	50
Total	121	out of	1363

Content History

Submissions
Submission Date	Submitter	Organization
2011-05-24 (CWE 1.13, 2011-06-01)	CWE Content Team	MITRE
2011-05-24 (CWE 1.13, 2011-06-01)
Modifications
Modification Date	Modifier	Organization
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Description, Name, References, View_Audience
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated View_Audience
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2019-01-03	Weaknesses Addressed by the CERT Java Secure Coding Standard

View Components

Weakness ID: 770

Vulnerability Mapping: ALLOWEDThis CWE ID may be used to map to real-world vulnerabilities
Abstraction: BaseBase - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.

View customized information:

For users who are interested in more notional aspects of a weakness. Example: educators, technical writers, and project/program managers. For users who are concerned with the practical application and details about the nature of a weakness and how to prevent it from happening. Example: tool developers, security researchers, pen-testers, incident response analysts. For users who are mapping an issue to CWE/CAPEC IDs, i.e., finding the most appropriate CWE for a specific issue (e.g., a CVE record). Example: tool developers, security researchers. For users who wish to see all available information for the CWE/CAPEC entry. For users who want to customize what details are displayed.

Description

Extended Description

Code frequently has to work with limited resources, so programmers must be careful to ensure that resources are not consumed too quickly, or too easily. Without use of quotas, resource limits, or other protection mechanisms, it can be easy for an attacker to consume many resources by rapidly making many requests, or causing larger resources to be used than is needed. When too many resources are allocated, or if a single resource is too large, then it can prevent the code from working correctly, possibly leading to a denial of service.

Common Consequences

This table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

Scope	Impact	Likelihood
Availability	Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other) When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource.

Potential Mitigations

Phase: Requirements

Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.

Phase: Architecture and Design

Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.

Phase: Architecture and Design

Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place, and it will help the administrator to identify who is committing the abuse. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.

Phase: Implementation

Strategy: Input Validation

Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.

When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."

Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

Note: This will only be applicable to cases where user input can influence the size or frequency of resource allocations.

Phase: Architecture and Design

For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

Phase: Architecture and Design

Mitigation of resource exhaustion attacks requires that the target system either:

recognizes the attack and denies that user further access for a given amount of time, typically by using increasing time delays

uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.

The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

The second solution can be difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply requires more resources on the part of the attacker.

Phase: Architecture and Design

Ensure that protocols have specific limits of scale placed on them.

Phases: Architecture and Design; Implementation

If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery.

Ensure that all failures in resource allocation place the system into a safe posture.

Phases: Operation; Architecture and Design

Strategy: Resource Limitation

Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems.

When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users.

Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).

Relationships

This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	665	Improper Initialization
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	400	Uncontrolled Resource Consumption
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	774	Allocation of File Descriptors or Handles Without Limits or Throttling
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	789	Memory Allocation with Excessive Size Value
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1325	Improperly Controlled Sequential Memory Allocation
CanFollow	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	20	Improper Input Validation

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	399	Resource Management Errors
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	840	Business Logic Errors

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	400	Uncontrolled Resource Consumption

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1011	Authorize Actors

Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

Phase	Note
Architecture and Design	OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Implementation
Operation
System Configuration

Applicable Platforms

This listing shows possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

Class: Not Language-Specific (Often Prevalent)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

This code allocates a socket and forks each time it receives a new connection.

(bad code)

Example Language: C

sock=socket(AF_INET, SOCK_STREAM, 0);
while (1) {

newsock=accept(sock, ...);
printf("A connection has been accepted\n");
pid = fork();

}

The program does not track how many connections have been made, and it does not limit the number of connections. Because forking is a relatively expensive operation, an attacker would be able to cause the system to run out of CPU, processes, or memory by making a large number of connections. Alternatively, an attacker could consume all available connections, preventing others from accessing the system remotely.

Example 2

In the following example a server socket connection is used to accept a request to store data on the local file system using a specified filename. The method openSocketConnection establishes a server socket to accept requests from a client. When a client establishes a connection to this service the getNextMessage method is first used to retrieve from the socket the name of the file to store the data, the openFileToWrite method will validate the filename and open a file to write to on the local file system. The getNextMessage is then used within a while loop to continuously read data from the socket and output the data to the file until there is no longer any data from the socket.

(bad code)

Example Language: C

int writeDataFromSocketToFile(char *host, int port)
{

char filename[FILENAME_SIZE];
char buffer[BUFFER_SIZE];
int socket = openSocketConnection(host, port);

if (socket < 0) {

printf("Unable to open socket connection");
return(FAIL);

}
if (getNextMessage(socket, filename, FILENAME_SIZE) > 0) {

if (openFileToWrite(filename) > 0) {

while (getNextMessage(socket, buffer, BUFFER_SIZE) > 0){

if (!(writeToFile(buffer) > 0))

break;

}

}
closeFile();

}
closeSocket(socket);

}

This example creates a situation where data can be dumped to a file on the local file system without any limits on the size of the file. This could potentially exhaust file or disk resources and/or limit other clients' ability to access the service.

Example 3

In the following example, the processMessage method receives a two dimensional character array containing the message to be processed. The two-dimensional character array contains the length of the message in the first character array and the message body in the second character array. The getMessageLength method retrieves the integer value of the length from the first character array. After validating that the message length is greater than zero, the body character array pointer points to the start of the second character array of the two-dimensional character array and memory is allocated for the new body character array.

(bad code)

Example Language: C

/* process message accepts a two-dimensional character array of the form [length][body] containing the message to be processed */
int processMessage(char **message)
{

char *body;

int length = getMessageLength(message[0]);

if (length > 0) {

body = &message[1][0];
processMessageBody(body);
return(SUCCESS);

}
else {

printf("Unable to process message; invalid message length");
return(FAIL);

}

This example creates a situation where the length of the body character array can be very large and will consume excessive memory, exhausting system resources. This can be avoided by restricting the length of the second character array with a maximum length check

Also, consider changing the type from 'int' to 'unsigned int', so that you are always guaranteed that the number is positive. This might not be possible if the protocol specifically requires allowing negative values, or if you cannot control the return value from getMessageLength(), but it could simplify the check to ensure the input is positive, and eliminate other errors such as signed-to-unsigned conversion errors (CWE-195) that may occur elsewhere in the code.

(good code)

Example Language: C

unsigned int length = getMessageLength(message[0]);
if ((length > 0) && (length < MAX_LENGTH)) {...}

Example 4

In the following example, a server object creates a server socket and accepts client connections to the socket. For every client connection to the socket a separate thread object is generated using the ClientSocketThread class that handles request made by the client through the socket.

(bad code)

Example Language: Java

public void acceptConnections() {

try {

ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
int counter = 0;
boolean hasConnections = true;
while (hasConnections) {

Socket client = serverSocket.accept();
Thread t = new Thread(new ClientSocketThread(client));
t.setName(client.getInetAddress().getHostName() + ":" + counter++);
t.start();

}
serverSocket.close();

} catch (IOException ex) {...}

}

In this example there is no limit to the number of client connections and client threads that are created. Allowing an unlimited number of client connections and threads could potentially overwhelm the system and system resources.

The server should limit the number of client connections and the client threads that are created. This can be easily done by creating a thread pool object that limits the number of threads that are generated.

(good code)

Example Language: Java

public static final int SERVER_PORT = 4444;
public static final int MAX_CONNECTIONS = 10;
...

public void acceptConnections() {

try {

ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
int counter = 0;
boolean hasConnections = true;
while (hasConnections) {

hasConnections = checkForMoreConnections();
Socket client = serverSocket.accept();
Thread t = new Thread(new ClientSocketThread(client));
t.setName(client.getInetAddress().getHostName() + ":" + counter++);
ExecutorService pool = Executors.newFixedThreadPool(MAX_CONNECTIONS);
pool.execute(t);

}
serverSocket.close();

} catch (IOException ex) {...}

}

Example 5

An unnamed web site allowed a user to purchase tickets for an event. A menu option allowed the user to purchase up to 10 tickets, but the back end did not restrict the actual number of tickets that could be purchased.

Example 5 References:

[REF-667] Rafal Los. "Real-Life Example of a 'Business Logic Defect' (Screen Shots!)". 2011. <http://h30501.www3.hp.com/t5/Following-the-White-Rabbit-A/Real-Life-Example-of-a-Business-Logic-Defect-Screen-Shots/ba-p/22581>.

Example 6

Here the problem is that every time a connection is made, more memory is allocated. So if one just opened up more and more connections, eventually the machine would run out of memory.

(bad code)

Example Language: C

bar connection() {

foo = malloc(1024);
return foo;

}

endConnection(bar foo) {

free(foo);

}

int main() {

while(1) {

foo=connection();

}

endConnection(foo)

}

Observed Examples

Reference	Description
CVE-2022-21668	Chain: Python library does not limit the resources used to process images that specify a very large number of bands (CWE-1284), leading to excessive memory consumption (CWE-789) or an integer overflow (CWE-190).
CVE-2009-4017	Language interpreter does not restrict the number of temporary files being created when handling a MIME request with a large number of parts..
CVE-2009-2726	Driver does not use a maximum width when invoking sscanf style functions, causing stack consumption.
CVE-2009-2540	Large integer value for a length property in an object causes a large amount of memory allocation.
CVE-2009-2054	Product allows exhaustion of file descriptors when processing a large number of TCP packets.
CVE-2008-5180	Communication product allows memory consumption with a large number of SIP requests, which cause many sessions to be created.
CVE-2008-1700	Product allows attackers to cause a denial of service via a large number of directives, each of which opens a separate window.
CVE-2005-4650	CMS does not restrict the number of searches that can occur simultaneously, leading to resource exhaustion.
CVE-2020-15100	web application scanner attempts to read an excessively large file created by a user, causing process termination
CVE-2020-7218	Go-based workload orchestrator does not limit resource usage with unauthenticated connections, allowing a DoS by flooding the service

Detection Methods

Manual Static Analysis

Manual static analysis can be useful for finding this weakness, but it might not achieve desired code coverage within limited time constraints. If denial-of-service is not considered a significant risk, or if there is strong emphasis on consequences such as code execution, then manual analysis may not focus on this weakness at all.

Fuzzing

While fuzzing is typically geared toward finding low-level implementation bugs, it can inadvertently find uncontrolled resource allocation problems. This can occur when the fuzzer generates a large number of test cases but does not restart the targeted product in between test cases. If an individual test case produces a crash, but it does not do so reliably, then an inability to limit resource allocation may be the cause.

When the allocation is directly affected by numeric inputs, then fuzzing may produce indications of this weakness.

Effectiveness: Opportunistic

Automated Dynamic Analysis

Certain automated dynamic analysis techniques may be effective in producing side effects of uncontrolled resource allocation problems, especially with resources such as processes, memory, and connections. The technique may involve generating a large number of requests to the product within a short time frame. Manual analysis is likely required to interpret the results.

Automated Static Analysis

Specialized configuration or tuning may be required to train automated tools to recognize this weakness.

Automated static analysis typically has limited utility in recognizing unlimited allocation problems, except for the missing release of program-independent system resources such as files, sockets, and processes, or unchecked arguments to memory. For system resources, automated static analysis may be able to detect circumstances in which resources are not released after they have expired, or if too much of a resource is requested at once, as can occur with memory. Automated analysis of configuration files may be able to detect settings that do not specify a maximum value.

Automated static analysis tools will not be appropriate for detecting exhaustion of custom resources, such as an intended security policy in which a bulletin board user is only allowed to make a limited number of posts per day.

Memberships

This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	802	2010 Top 25 - Risky Resource Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	857	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	858	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	861	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	867	2011 Top 25 - Weaknesses On the Cusp
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	876	CERT C++ Secure Coding Section 08 - Memory Management (MEM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	877	CERT C++ Secure Coding Section 09 - Input Output (FIO)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	985	SFP Secondary Cluster: Unrestricted Consumption
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1147	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 13. Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1148	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 14. Serialization (SER)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1152	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 49. Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1416	Comprehensive Categorization: Resource Lifecycle Management

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Notes

Relationship

This entry is different from uncontrolled resource consumption (CWE-400) in that there are other weaknesses that are related to inability to control resource consumption, such as holding on to a resource too long after use, or not correctly keeping track of active resources so that they can be managed and released when they are finished (CWE-771).

Theoretical

Vulnerability theory is largely about how behaviors and resources interact. "Resource exhaustion" can be regarded as either a consequence or an attack, depending on the perspective. This entry is an attempt to reflect one of the underlying weaknesses that enable these attacks (or consequences) to take place.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
The CERT Oracle Secure Coding Standard for Java (2011)	FIO04-J	Close resources when they are no longer needed
The CERT Oracle Secure Coding Standard for Java (2011)	SER12-J	Avoid memory and resource leaks during serialization
The CERT Oracle Secure Coding Standard for Java (2011)	MSC05-J	Do not exhaust heap space
ISA/IEC 62443	Part 4-2	Req CR 7.2
ISA/IEC 62443	Part 4-2	Req CR 2.7
ISA/IEC 62443	Part 4-1	Req SI-1
ISA/IEC 62443	Part 4-1	Req SI-2
ISA/IEC 62443	Part 3-3	Req SR 7.2
ISA/IEC 62443	Part 3-3	Req SR 2.7

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-125	Flooding
CAPEC-130	Excessive Allocation
CAPEC-147	XML Ping of the Death
CAPEC-197	Exponential Data Expansion
CAPEC-229	Serialized Data Parameter Blowup
CAPEC-230	Serialized Data with Nested Payloads
CAPEC-231	Oversized Serialized Data Payloads
CAPEC-469	HTTP DoS
CAPEC-482	TCP Flood
CAPEC-486	UDP Flood
CAPEC-487	ICMP Flood
CAPEC-488	HTTP Flood
CAPEC-489	SSL Flood
CAPEC-490	Amplification
CAPEC-491	Quadratic Data Expansion
CAPEC-493	SOAP Array Blowup
CAPEC-494	TCP Fragmentation
CAPEC-495	UDP Fragmentation
CAPEC-496	ICMP Fragmentation
CAPEC-528	XML Flood

References

[REF-386] Joao Antunes, Nuno Ferreira Neves and Paulo Verissimo. "Detection and Prediction of Resource-Exhaustion Vulnerabilities". Proceedings of the IEEE International Symposium on Software Reliability Engineering (ISSRE). 2008-11. <http://homepages.di.fc.ul.pt/~nuno/PAPERS/ISSRE08.pdf>.

[REF-387] D.J. Bernstein. "Resource exhaustion". <http://cr.yp.to/docs/resources.html>.

[REF-388] Pascal Meunier. "Resource exhaustion". Secure Programming Educational Material. 2004. <http://homes.cerias.purdue.edu/~pmeunier/secprog/sanitized/class1/6.resource%20exhaustion.ppt>.

[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 17, "Protecting Against Denial of Service Attacks" Page 517. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.

[REF-672] Frank Kim. "Top 25 Series - Rank 22 - Allocation of Resources Without Limits or Throttling". SANS Software Security Institute. 2010-03-23. <https://web.archive.org/web/20170113055136/https://software-security.sans.org/blog/2010/03/23/top-25-series-rank-22-allocation-of-resources-without-limits-or-throttling/>. URL validated: 2023-04-07.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 10, "Resource Limits", Page 574. 1st Edition. Addison Wesley. 2006.

Content History

Submissions
Submission Date	Submitter	Organization
2009-05-13 (CWE 1.4, 2009-05-27)	CWE Content Team	MITRE
2009-05-13 (CWE 1.4, 2009-05-27)
Contributions
Contribution Date	Contributor	Organization
2023-11-14 (CWE 4.14, 2024-02-29)	participants in the CWE ICS/OT SIG 62443 Mapping Fall Workshop
2023-11-14 (CWE 4.14, 2024-02-29)	Contributed or reviewed taxonomy mappings for ISA/IEC 62443
Modifications
Modification Date	Modifier	Organization
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Related_Attack_Patterns
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Relationships
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Applicable_Platforms, Demonstrative_Examples, Detection_Factors, Observed_Examples, References, Time_of_Introduction
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Common_Consequences, Detection_Factors, Potential_Mitigations, References, Related_Attack_Patterns, Relationships
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Common_Consequences, Demonstrative_Examples, Related_Attack_Patterns
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, Potential_Mitigations, References
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Demonstrative_Examples, Potential_Mitigations
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Demonstrative_Examples, Detection_Factors, Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, References, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Related_Attack_Patterns
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Related_Attack_Patterns
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Related_Attack_Patterns
2017-05-03	CWE Content Team	MITRE
2017-05-03	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Demonstrative_Examples, Likelihood_of_Exploit, Modes_of_Introduction, Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Demonstrative_Examples, Description, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Related_Attack_Patterns, Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Potential_Mitigations, Related_Attack_Patterns, Relationships
2020-06-25	CWE Content Team	MITRE
2020-06-25	updated Applicable_Platforms, Description, Maintenance_Notes, Potential_Mitigations, Relationship_Notes, Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Observed_Examples
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Observed_Examples, References
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description, Detection_Factors
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Taxonomy_Mappings

Weakness ID: 405

Vulnerability Mapping: ALLOWEDThis CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review (with careful review of mapping notes)
Abstraction: ClassClass - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.

View customized information:

Description

Extended Description

This can lead to poor performance due to "amplification" of resource consumption, typically in a non-linear fashion. This situation is worsened if the product allows malicious users or attackers to consume more resources than their access level permits.

Common Consequences

Scope	Impact	Likelihood
Availability	Technical Impact: DoS: Amplification; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other) Sometimes this is a factor in "flood" attacks, but other types of amplification exist.	High

Potential Mitigations

Phase: Architecture and Design

An application must make resources available to a client commensurate with the client's access level.

Phase: Architecture and Design

An application must, at all times, keep track of allocated resources and meter their usage appropriately.

Phase: System Configuration

Consider disabling resource-intensive algorithms on the server side, such as Diffie-Hellman key exchange.

Effectiveness: High

Note: Business requirements may prevent disabling resource-intensive algorithms.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	400	Uncontrolled Resource Consumption
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	406	Insufficient Control of Network Message Volume (Network Amplification)
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	407	Inefficient Algorithmic Complexity
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	408	Incorrect Behavior Order: Early Amplification
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	409	Improper Handling of Highly Compressed Data (Data Amplification)
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	776	Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1050	Excessive Platform Resource Consumption within a Loop
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1072	Data Resource Access without Use of Connection Pooling
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1073	Non-SQL Invokable Control Element with Excessive Number of Data Resource Accesses
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1084	Invokable Control Element with Excessive File or Data Access Operations
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1089	Large Data Table with Excessive Number of Indices
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1094	Excessive Index Range Scan for a Data Resource
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	1176	Inefficient CPU Computation
PeerOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	404	Improper Resource Shutdown or Release

Modes Of Introduction

Phase	Note
Architecture and Design
Implementation
Operation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Operating Systems

Class: Not OS-Specific (Undetermined Prevalence)

Architectures

Class: Not Architecture-Specific (Undetermined Prevalence)

Technologies

Class: Not Technology-Specific (Undetermined Prevalence)

Class: Client Server (Undetermined Prevalence)

Demonstrative Examples

Example 1

This code listens on a port for DNS requests and sends the result to the requesting address.

(bad code)

Example Language: Python

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind( (UDP_IP,UDP_PORT) )
while true:

data = sock.recvfrom(1024)
if not data:

break

(requestIP, nameToResolve) = parseUDPpacket(data)
record = resolveName(nameToResolve)
sendResponse(requestIP,record)

This code sends a DNS record to a requesting IP address. UDP allows the source IP address to be easily changed ('spoofed'), thus allowing an attacker to redirect responses to a target, which may be then be overwhelmed by the network traffic.

Example 2

This function prints the contents of a specified file requested by a user.

(bad code)

Example Language: PHP

function printFile($username,$filename){

//read file into string
$file = file_get_contents($filename);
if ($file && isOwnerOf($username,$filename)){

echo $file;
return true;

}
else{

echo 'You are not authorized to view this file';

}
return false;

}

This code first reads a specified file into memory, then prints the file if the user is authorized to see its contents. The read of the file into memory may be resource intensive and is unnecessary if the user is not allowed to see the file anyway.

Example 3

The DTD and the very brief XML below illustrate what is meant by an XML bomb. The ZERO entity contains one character, the letter A. The choice of entity name ZERO is being used to indicate length equivalent to that exponent on two, that is, the length of ZERO is 2^0. Similarly, ONE refers to ZERO twice, therefore the XML parser will expand ONE to a length of 2, or 2^1. Ultimately, we reach entity THIRTYTWO, which will expand to 2^32 characters in length, or 4 GB, probably consuming far more data than expected.

(attack code)

Example Language: XML

<?xml version="1.0"?>
<!DOCTYPE MaliciousDTD [
<!ENTITY ZERO "A">
<!ENTITY ONE "&ZERO;&ZERO;">
<!ENTITY TWO "&ONE;&ONE;">
...
<!ENTITY THIRTYTWO "&THIRTYONE;&THIRTYONE;">
]>
<data>&THIRTYTWO;</data>

Example 4

This example attempts to check if an input string is a "sentence" [REF-1164].

(bad code)

Example Language: JavaScript

var test_string = "Bad characters: $@#";
var bad_pattern = /^(\w+\s?)*$/i;
var result = test_string.search(bad_pattern);

The regular expression has a vulnerable backtracking clause inside (\w+\s?)*$ which can be triggered to cause a Denial of Service by processing particular phrases.

To fix the backtracking problem, backtracking is removed with the ?= portion of the expression which changes it to a lookahead and the \2 which prevents the backtracking. The modified example is:

(good code)

Example Language: JavaScript

var test_string = "Bad characters: $@#";
var good_pattern = /^((?=(\w+))\2\s?)*$/i;
var result = test_string.search(good_pattern);

Note that [REF-1164] has a more thorough (and lengthy) explanation of everything going on within the RegEx.

Example 5

An adversary can cause significant resource consumption on a server by filtering the cryptographic algorithms offered by the client to the ones that are the most resource-intensive on the server side. After discovering which cryptographic algorithms are supported by the server, a malicious client can send the initial cryptographic handshake messages that contains only the resource-intensive algorithms. For some cryptographic protocols, these messages can be completely prefabricated, as the resource-intensive part of the handshake happens on the server-side first (such as TLS), rather than on the client side. In the case of cryptographic protocols where the resource-intensive part should happen on the client-side first (such as SSH), a malicious client can send a forged/precalculated computation result, which seems correct to the server, so the resource-intensive part of the handshake is going to happen on the server side. A malicious client is required to send only the initial messages of a cryptographic handshake to initiate the resource-consuming part of the cryptographic handshake. These messages are usually small, and generating them requires minimal computational effort, enabling a denial-of-service attack. An additional risk is the fact that higher key size increases the effectiveness of the attack. Cryptographic protocols where the clients have influence over the size of the used key (such as TLS 1.3 or SSH) are most at risk, as the client can enforce the highest key size supported by the server.

Observed Examples

Reference	Description
CVE-1999-0513	Classic "Smurf" attack, using spoofed ICMP packets to broadcast addresses.
CVE-2003-1564	Parsing library allows XML bomb
CVE-2004-2458	Tool creates directories before authenticating user.
CVE-2020-10735	Python has "quadratic complexity" issue when converting string to int with many digits in unexpected bases
CVE-2020-5243	server allows ReDOS with crafted User-Agent strings, due to overlapping capture groups that cause excessive backtracking.
CVE-2013-5211	composite: NTP feature generates large responses (high amplification factor) with spoofed UDP source addresses.
CVE-2002-20001	Diffie-Hellman (DHE) Key Agreement Protocol allows attackers to send arbitrary numbers that are not public keys, which causes the server to perform expensive, unnecessary computation of modular exponentiation.
CVE-2022-40735	The Diffie-Hellman Key Agreement Protocol allows use of long exponents, which are more computationally expensive than using certain "short exponents" with particular properties.

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	730	OWASP Top Ten 2004 Category A9 - Denial of Service
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	855	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 12 - Thread Pools (TPS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	857	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	977	SFP Secondary Cluster: Design
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1145	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 11. Thread Pools (TPS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1147	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 13. Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1416	Comprehensive Categorization: Resource Lifecycle Management

Vulnerability Mapping Notes

Usage: ALLOWED-WITH-REVIEW

(this CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review)

Reason: Abstraction

Rationale:

This CWE entry is a Class and might have Base-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
PLOVER			Asymmetric resource consumption (amplification)
OWASP Top Ten 2004	A9	CWE More Specific	Denial of Service
WASC	41		XML Attribute Blowup
The CERT Oracle Secure Coding Standard for Java (2011)	TPS00-J		Use thread pools to enable graceful degradation of service during traffic bursts
The CERT Oracle Secure Coding Standard for Java (2011)	FIO04-J		Release resources when they are no longer needed

References

[REF-1164] Ilya Kantor. "Catastrophic backtracking". 2020-12-13. <https://javascript.info/regexp-catastrophic-backtracking>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	PLOVER
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2021-11-11	Szilárd Pfeiffer	Balasys IT Security
2021-11-11	Submitted content that led to modifications in applicable platforms, common consequences, potential mitigations, demonstrative examples, observed examples.
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships, Other_Notes, Taxonomy_Mappings
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Description
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Common_Consequences, Other_Notes
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Taxonomy_Mappings
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Description
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Common_Consequences
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, Functional_Areas
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Description, Observed_Examples, Potential_Mitigations, References, Time_of_Introduction
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Demonstrative_Examples

Weakness ID: 319

View customized information:

Description

The product transmits sensitive or security-critical data in cleartext in a communication channel that can be sniffed by unauthorized actors.

Extended Description

Many communication channels can be "sniffed" (monitored) by adversaries during data transmission. For example, in networking, packets can traverse many intermediary nodes from the source to the destination, whether across the internet, an internal network, the cloud, etc. Some actors might have privileged access to a network interface or any link along the channel, such as a router, but they might not be authorized to collect the underlying data. As a result, network traffic could be sniffed by adversaries, spilling security-critical data.

Applicable communication channels are not limited to software products. Applicable channels include hardware-specific technologies such as internal hardware networks and external debug channels, supporting remote JTAG debugging. When mitigations are not applied to combat adversaries within the product's threat model, this weakness significantly lowers the difficulty of exploitation by such adversaries.

When full communications are recorded or logged, such as with a packet dump, an adversary could attempt to obtain the dump long after the transmission has occurred and try to "sniff" the cleartext from the recorded communications in the dump itself. Even if the information is encoded in a way that is not human-readable, certain techniques could determine which encoding is being used, then decode the information.

Common Consequences

Scope	Impact	Likelihood
Integrity Confidentiality	Technical Impact: Read Application Data; Modify Files or Directories Anyone can read the information by gaining access to the channel being used for communication.

Potential Mitigations

Phase: Architecture and Design

Before transmitting, encrypt the data using reliable, confidentiality-protecting cryptographic protocols.

Phase: Implementation

When using web applications with SSL, use SSL for the entire session from login to logout, not just for the initial login page.

Phase: Implementation

When designing hardware platforms, ensure that approved encryption algorithms (such as those recommended by NIST) protect paths from security critical data to trusted user applications.

Phase: Testing

Use tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session. These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Phase: Operation

Configure servers to use encrypted channels for communication, which may include SSL or other secure protocols.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	311	Missing Encryption of Sensitive Data
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	5	J2EE Misconfiguration: Data Transmission Without Encryption
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	614	Sensitive Cookie in HTTPS Session Without 'Secure' Attribute

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	199	Information Management Errors

Relevant to the view "Hardware Design" (CWE-1194)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1207	Debug and Test Problems

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	311	Missing Encryption of Sensitive Data

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1013	Encrypt Data

Modes Of Introduction

Phase	Note
Architecture and Design	OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Architecture and Design	For hardware, this may be introduced when design does not plan for an attacker having physical access while a legitimate user is remotely operating the device.
Operation
System Configuration

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: Cloud Computing (Undetermined Prevalence)

Class: Mobile (Undetermined Prevalence)

Class: ICS/OT (Often Prevalent)

Class: System on Chip (Undetermined Prevalence)

Test/Debug Hardware (Often Prevalent)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

The following code attempts to establish a connection to a site to communicate sensitive information.

(bad code)

Example Language: Java

try {

URL u = new URL("http://www.secret.example.org/");
HttpURLConnection hu = (HttpURLConnection) u.openConnection();
hu.setRequestMethod("PUT");
hu.connect();
OutputStream os = hu.getOutputStream();
hu.disconnect();

}
catch (IOException e) {

//...

}

Though a connection is successfully made, the connection is unencrypted and it is possible that all sensitive data sent to or received from the server will be read by unintended actors.

Example 2

In 2022, the OT:ICEFALL study examined products by 10 different Operational Technology (OT) vendors. The researchers reported 56 vulnerabilities and said that the products were "insecure by design" [REF-1283]. If exploited, these vulnerabilities often allowed adversaries to change how the products operated, ranging from denial of service to changing the code that the products executed. Since these products were often used in industries such as power, electrical, water, and others, there could even be safety implications.

Multiple vendors used cleartext transmission of sensitive information in their OT products.

Example 3

A TAP accessible register is read/written by a JTAG based tool, for internal use by authorized users. However, an adversary can connect a probing device and collect the values from the unencrypted channel connecting the JTAG interface to the authorized user, if no additional protections are employed.

Example 4

The following Azure CLI command lists the properties of a particular storage account:

(informative)

Example Language: Shell

az storage account show -g {ResourceGroupName} -n {StorageAccountName}

The JSON result might be:

(bad code)

Example Language: JSON

{

"name": "{StorageAccountName}",
"enableHttpsTrafficOnly": false,
"type": "Microsoft.Storage/storageAccounts"

}

The enableHttpsTrafficOnly value is set to false, because the default setting for Secure transfer is set to Disabled. This allows cloud storage resources to successfully connect and transfer data without the use of encryption (e.g., HTTP, SMB 2.1, SMB 3.0, etc.).

Azure's storage accounts can be configured to only accept requests from secure connections made over HTTPS. The secure transfer setting can be enabled using Azure's Portal (GUI) or programmatically by setting the enableHttpsTrafficOnly property to True on the storage account, such as:

(good code)

Example Language: Shell

az storage account update -g {ResourceGroupName} -n {StorageAccountName} --https-only true

The change can be confirmed from the result by verifying that the enableHttpsTrafficOnly value is true:

(good code)

Example Language: JSON

{

"name": "{StorageAccountName}",
"enableHttpsTrafficOnly": true,
"type": "Microsoft.Storage/storageAccounts"

}

Note: to enable secure transfer using Azure's Portal instead of the command line:

Open the Create storage account pane in the Azure portal.
In the Advanced page, select the Enable secure transfer checkbox.

Observed Examples

Reference	Description
CVE-2022-29519	Programmable Logic Controller (PLC) sends sensitive information in plaintext, including passwords and session tokens.
CVE-2022-30312	Building Controller uses a protocol that transmits authentication credentials in plaintext.
CVE-2022-31204	Programmable Logic Controller (PLC) sends password in plaintext.
CVE-2002-1949	Passwords transmitted in cleartext.
CVE-2008-4122	Chain: Use of HTTPS cookie without "secure" flag causes it to be transmitted across unencrypted HTTP.
CVE-2008-3289	Product sends password hash in cleartext in violation of intended policy.
CVE-2008-4390	Remote management feature sends sensitive information including passwords in cleartext.
CVE-2007-5626	Backup routine sends password in cleartext in email.
CVE-2004-1852	Product transmits Blowfish encryption key in cleartext.
CVE-2008-0374	Printer sends configuration information, including administrative password, in cleartext.
CVE-2007-4961	Chain: cleartext transmission of the MD5 hash of password enables attacks against a server that is susceptible to replay (CWE-294).
CVE-2007-4786	Product sends passwords in cleartext to a log server.
CVE-2005-3140	Product sends file with cleartext passwords in e-mail message intended for diagnostic purposes.

Detection Methods

Black Box

Use monitoring tools that examine the software's process as it interacts with the operating system and the network. This technique is useful in cases when source code is unavailable, if the software was not developed by you, or if you want to verify that the build phase did not introduce any new weaknesses. Examples include debuggers that directly attach to the running process; system-call tracing utilities such as truss (Solaris) and strace (Linux); system activity monitors such as FileMon, RegMon, Process Monitor, and other Sysinternals utilities (Windows); and sniffers and protocol analyzers that monitor network traffic.

Attach the monitor to the process, trigger the feature that sends the data, and look for the presence or absence of common cryptographic functions in the call tree. Monitor the network and determine if the data packets contain readable commands. Tools exist for detecting if certain encodings are in use. If the traffic contains high entropy, this might indicate the usage of encryption.

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	751	2009 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	818	OWASP Top Ten 2010 Category A9 - Insufficient Transport Layer Protection
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	858	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	859	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 16 - Platform Security (SEC)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	934	OWASP Top Ten 2013 Category A6 - Sensitive Data Exposure
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	963	SFP Secondary Cluster: Exposed Data
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1029	OWASP Top Ten 2017 Category A3 - Sensitive Data Exposure
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1148	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 14. Serialization (SER)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1346	OWASP Top Ten 2021 Category A02:2021 - Cryptographic Failures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1366	ICS Communications: Frail Security in Protocols
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1402	Comprehensive Categorization: Encryption

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Maintenance

The Taxonomy_Mappings to ISA/IEC 62443 were added in CWE 4.10, but they are still under review and might change in future CWE versions. These draft mappings were performed by members of the "Mapping CWE to 62443" subgroup of the CWE-CAPEC ICS/OT Special Interest Group (SIG), and their work is incomplete as of CWE 4.10. The mappings are included to facilitate discussion and review by the broader ICS/OT community, and they are likely to change in future CWE versions.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
PLOVER		Plaintext Transmission of Sensitive Information
The CERT Oracle Secure Coding Standard for Java (2011)	SEC06-J	Do not rely on the default automatic signature verification provided by URLClassLoader and java.util.jar
The CERT Oracle Secure Coding Standard for Java (2011)	SER02-J	Sign then seal sensitive objects before sending them outside a trust boundary
Software Fault Patterns	SFP23	Exposed Data
ISA/IEC 62443	Part 3-3	Req SR 4.1
ISA/IEC 62443	Part 4-2	Req CR 4.1B

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-102	Session Sidejacking
CAPEC-117	Interception
CAPEC-383	Harvesting Information via API Event Monitoring
CAPEC-477	Signature Spoofing by Mixing Signed and Unsigned Content
CAPEC-65	Sniff Application Code

References

[REF-271] OWASP. "Top 10 2007-Insecure Communications". 2007. <http://www.owasp.org/index.php/Top_10_2007-A9>.

[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 9, "Protecting Secret Data" Page 299. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 22: Failing to Protect Network Traffic." Page 337. McGraw-Hill. 2010.

[REF-172] Chris Wysopal. "Mobile App Top 10 List". 2010-12-13. <https://www.veracode.com/blog/2010/12/mobile-app-top-10-list>. URL validated: 2023-04-07.

[REF-1283] Forescout Vedere Labs. "OT:ICEFALL: The legacy of "insecure by design" and its implications for certifications and risk management". 2022-06-20. <https://www.forescout.com/resources/ot-icefall-report/>.

[REF-1307] Center for Internet Security. "CIS Microsoft Azure Foundations Benchmark version 1.5.0". Sections 3.1 and 3.10. 2022-08-16. <https://www.cisecurity.org/benchmark/azure>. URL validated: 2023-01-19.

[REF-1309] Microsoft. "Require secure transfer to ensure secure connections". 2022-07-24. <https://learn.microsoft.com/en-us/azure/storage/common/storage-require-secure-transfer>. URL validated: 2023-01-24.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	PLOVER
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2023-01-24	Accellera IP Security Assurance (IPSA) Working Group	Accellera Systems Initiative
2023-01-24	Submitted original contents of CWE-1324 and reviewed its integration into this entry.
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships, Taxonomy_Mappings
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Common_Consequences, Description, Likelihood_of_Exploit, Name, Observed_Examples, Potential_Mitigations, References, Relationships
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Related_Attack_Patterns
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated References
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Applicable_Platforms, Common_Consequences, Time_of_Introduction
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Detection_Factors, Relationships
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Observed_Examples, Related_Attack_Patterns
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Potential_Mitigations
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, References, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2013-02-21	CWE Content Team	MITRE
2013-02-21	updated Applicable_Platforms, References
2013-07-17	CWE Content Team	MITRE
2013-07-17	updated Relationships
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Related_Attack_Patterns
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2017-05-03	CWE Content Team	MITRE
2017-05-03	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Likelihood_of_Exploit, Modes_of_Introduction, References, Relationships
2018-01-23	CWE Content Team	MITRE
2018-01-23	updated Abstraction
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References, Relationships, Type
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships, Type
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Related_Attack_Patterns, Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-06-28	CWE Content Team	MITRE
2022-06-28	updated Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Applicable_Platforms, Demonstrative_Examples, Observed_Examples, References
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Applicable_Platforms, Demonstrative_Examples, Description, Maintenance_Notes, Modes_of_Introduction, Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Description, Mapping_Notes, Relationships
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Demonstrative_Examples
Previous Entry Names
Change Date	Previous Entry Name
2009-01-12	Plaintext Transmission of Sensitive Information

Weakness ID: 362

View customized information:

Description

Extended Description

This can have security implications when the expected synchronization is in security-critical code, such as recording whether a user is authenticated or modifying important state information that should not be influenced by an outsider.

A race condition occurs within concurrent environments, and is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc.

A race condition violates these properties, which are closely related:

Exclusivity - the code sequence is given exclusive access to the shared resource, i.e., no other code sequence can modify properties of the shared resource before the original sequence has completed execution.
Atomicity - the code sequence is behaviorally atomic, i.e., no other thread or process can concurrently execute the same sequence of instructions (or a subset) against the same resource.

A race condition exists when an "interfering code sequence" can still access the shared resource, violating exclusivity. Programmers may assume that certain code sequences execute too quickly to be affected by an interfering code sequence; when they are not, this violates atomicity. For example, the single "x++" statement may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read (the original value of x), followed by a computation (x+1), followed by a write (save the result to x).

The interfering code sequence could be "trusted" or "untrusted." A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.

Common Consequences

Scope	Impact	Likelihood
Availability	Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other) When a race condition makes it possible to bypass a resource cleanup routine or trigger multiple initialization routines, it may lead to resource exhaustion (CWE-400).
Availability	Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability When a race condition allows multiple control flows to access a resource simultaneously, it might lead the product(s) into unexpected states, possibly resulting in a crash.
Confidentiality Integrity	Technical Impact: Read Files or Directories; Read Application Data When a race condition is combined with predictable resource names and loose permissions, it may be possible for an attacker to overwrite or access confidential data (CWE-59).

Potential Mitigations

Phase: Architecture and Design

In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.

Phase: Architecture and Design

Use thread-safe capabilities such as the data access abstraction in Spring.

Phase: Architecture and Design

Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.

Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

Phase: Implementation

When using multithreading and operating on shared variables, only use thread-safe functions.

Phase: Implementation

Use atomic operations on shared variables. Be wary of innocent-looking constructs such as "x++". This may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read, followed by a computation, followed by a write.

Phase: Implementation

Use a mutex if available, but be sure to avoid related weaknesses such as CWE-412.

Phase: Implementation

Avoid double-checked locking (CWE-609) and other implementation errors that arise when trying to avoid the overhead of synchronization.

Phase: Implementation

Disable interrupts or signals over critical parts of the code, but also make sure that the code does not go into a large or infinite loop.

Phase: Implementation

Use the volatile type modifier for critical variables to avoid unexpected compiler optimization or reordering. This does not necessarily solve the synchronization problem, but it can help.

Phases: Architecture and Design; Operation

Strategy: Environment Hardening

Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	691	Insufficient Control Flow Management
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	364	Signal Handler Race Condition
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	366	Race Condition within a Thread
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	367	Time-of-check Time-of-use (TOCTOU) Race Condition
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	368	Context Switching Race Condition
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	421	Race Condition During Access to Alternate Channel
ParentOf	Composite - a Compound Element that consists of two or more distinct weaknesses, in which all weaknesses must be present at the same time in order for a potential vulnerability to arise. Removing any of the weaknesses eliminates or sharply reduces the risk. One weakness, X, can be "broken down" into component weaknesses Y and Z. There can be cases in which one weakness might not be essential to a composite, but changes the nature of the composite when it becomes a vulnerability.	689	Permission Race Condition During Resource Copy
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1223	Race Condition for Write-Once Attributes
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1298	Hardware Logic Contains Race Conditions
CanFollow	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	662	Improper Synchronization
CanPrecede	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	416	Use After Free
CanPrecede	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	476	NULL Pointer Dereference

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	367	Time-of-check Time-of-use (TOCTOU) Race Condition

Modes Of Introduction

Phase	Note
Architecture and Design
Implementation

Applicable Platforms

Languages

C (Sometimes Prevalent)

C++ (Sometimes Prevalent)

Java (Sometimes Prevalent)

Technologies

Class: Mobile (Undetermined Prevalence)

Class: ICS/OT (Undetermined Prevalence)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

This code could be used in an e-commerce application that supports transfers between accounts. It takes the total amount of the transfer, sends it to the new account, and deducts the amount from the original account.

(bad code)

Example Language: Perl

$transfer_amount = GetTransferAmount();
$balance = GetBalanceFromDatabase();

if ($transfer_amount < 0) {

FatalError("Bad Transfer Amount");

}
$newbalance = $balance - $transfer_amount;
if (($balance - $transfer_amount) < 0) {

FatalError("Insufficient Funds");

}
SendNewBalanceToDatabase($newbalance);
NotifyUser("Transfer of $transfer_amount succeeded.");
NotifyUser("New balance: $newbalance");

A race condition could occur between the calls to GetBalanceFromDatabase() and SendNewBalanceToDatabase().

Suppose the balance is initially 100.00. An attack could be constructed as follows:

(attack code)

Example Language: Other

In the following pseudocode, the attacker makes two simultaneous calls of the program, CALLER-1 and CALLER-2. Both callers are for the same user account.
CALLER-1 (the attacker) is associated with PROGRAM-1 (the instance that handles CALLER-1). CALLER-2 is associated with PROGRAM-2.
CALLER-1 makes a transfer request of 80.00.
PROGRAM-1 calls GetBalanceFromDatabase and sets $balance to 100.00
PROGRAM-1 calculates $newbalance as 20.00, then calls SendNewBalanceToDatabase().
Due to high server load, the PROGRAM-1 call to SendNewBalanceToDatabase() encounters a delay.
CALLER-2 makes a transfer request of 1.00.
PROGRAM-2 calls GetBalanceFromDatabase() and sets $balance to 100.00. This happens because the previous PROGRAM-1 request was not processed yet.
PROGRAM-2 determines the new balance as 99.00.
After the initial delay, PROGRAM-1 commits its balance to the database, setting it to 20.00.
PROGRAM-2 sends a request to update the database, setting the balance to 99.00

At this stage, the attacker should have a balance of 19.00 (due to 81.00 worth of transfers), but the balance is 99.00, as recorded in the database.

To prevent this weakness, the programmer has several options, including using a lock to prevent multiple simultaneous requests to the web application, or using a synchronization mechanism that includes all the code between GetBalanceFromDatabase() and SendNewBalanceToDatabase().

Example 2

The following function attempts to acquire a lock in order to perform operations on a shared resource.

(bad code)

Example Language: C

void f(pthread_mutex_t *mutex) {

pthread_mutex_lock(mutex);

/* access shared resource */

pthread_mutex_unlock(mutex);

}

However, the code does not check the value returned by pthread_mutex_lock() for errors. If pthread_mutex_lock() cannot acquire the mutex for any reason, the function may introduce a race condition into the program and result in undefined behavior.

In order to avoid data races, correctly written programs must check the result of thread synchronization functions and appropriately handle all errors, either by attempting to recover from them or reporting them to higher levels.

(good code)

Example Language: C

int f(pthread_mutex_t *mutex) {

int result;

result = pthread_mutex_lock(mutex);
if (0 != result)

return result;

/* access shared resource */

return pthread_mutex_unlock(mutex);

}

Example 3

Suppose a processor's Memory Management Unit (MMU) has 5 other shadow MMUs to distribute its workload for its various cores. Each MMU has the start address and end address of "accessible" memory. Any time this accessible range changes (as per the processor's boot status), the main MMU sends an update message to all the shadow MMUs.

Suppose the interconnect fabric does not prioritize such "update" packets over other general traffic packets. This introduces a race condition. If an attacker can flood the target with enough messages so that some of those attack packets reach the target before the new access ranges gets updated, then the attacker can leverage this scenario.

Observed Examples

Reference	Description
CVE-2022-29527	Go application for cloud management creates a world-writable sudoers file that allows local attackers to inject sudo rules and escalate privileges to root by winning a race condition.
CVE-2021-1782	Chain: improper locking (CWE-667) leads to race condition (CWE-362), as exploited in the wild per CISA KEV.
CVE-2021-0920	Chain: mobile platform race condition (CWE-362) leading to use-after-free (CWE-416), as exploited in the wild per CISA KEV.
CVE-2020-6819	Chain: race condition (CWE-362) leads to use-after-free (CWE-416), as exploited in the wild per CISA KEV.
CVE-2019-18827	chain: JTAG interface is not disabled (CWE-1191) during ROM code execution, introducing a race condition (CWE-362) to extract encryption keys
CVE-2019-1161	Chain: race condition (CWE-362) in anti-malware product allows deletion of files by creating a junction (CWE-1386) and using hard links during the time window in which a temporary file is created and deleted.
CVE-2015-1743	TOCTOU in sandbox process allows installation of untrusted browser add-ons by replacing a file after it has been verified, but before it is executed
CVE-2014-8273	Chain: chipset has a race condition (CWE-362) between when an interrupt handler detects an attempt to write-enable the BIOS (in violation of the lock bit), and when the handler resets the write-enable bit back to 0, allowing attackers to issue BIOS writes during the timing window [REF-1237].
CVE-2008-5044	Race condition leading to a crash by calling a hook removal procedure while other activities are occurring at the same time.
CVE-2008-2958	chain: time-of-check time-of-use (TOCTOU) race condition in program allows bypass of protection mechanism that was designed to prevent symlink attacks.
CVE-2008-1570	chain: time-of-check time-of-use (TOCTOU) race condition in program allows bypass of protection mechanism that was designed to prevent symlink attacks.
CVE-2008-0058	Unsynchronized caching operation enables a race condition that causes messages to be sent to a deallocated object.
CVE-2008-0379	Race condition during initialization triggers a buffer overflow.
CVE-2007-6599	Daemon crash by quickly performing operations and undoing them, which eventually leads to an operation that does not acquire a lock.
CVE-2007-6180	chain: race condition triggers NULL pointer dereference
CVE-2007-5794	Race condition in library function could cause data to be sent to the wrong process.
CVE-2007-3970	Race condition in file parser leads to heap corruption.
CVE-2008-5021	chain: race condition allows attacker to access an object while it is still being initialized, causing software to access uninitialized memory.
CVE-2009-4895	chain: race condition for an argument value, possibly resulting in NULL dereference
CVE-2009-3547	chain: race condition might allow resource to be released before operating on it, leading to NULL dereference
CVE-2006-5051	Chain: Signal handler contains too much functionality (CWE-828), introducing a race condition (CWE-362) that leads to a double free (CWE-415).

Detection Methods

Black Box

Black box methods may be able to identify evidence of race conditions via methods such as multiple simultaneous connections, which may cause the software to become instable or crash. However, race conditions with very narrow timing windows would not be detectable.

White Box

Common idioms are detectable in white box analysis, such as time-of-check-time-of-use (TOCTOU) file operations (CWE-367), or double-checked locking (CWE-609).

Automated Dynamic Analysis

This weakness can be detected using dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

Race conditions may be detected with a stress-test by calling the software simultaneously from a large number of threads or processes, and look for evidence of any unexpected behavior.

Insert breakpoints or delays in between relevant code statements to artificially expand the race window so that it will be easier to detect.

Effectiveness: Moderate

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Bytecode Weakness Analysis - including disassembler + source code weakness analysis

Cost effective for partial coverage:

Binary Weakness Analysis - including disassembler + source code weakness analysis

Effectiveness: High

Dynamic Analysis with Automated Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Web Application Scanner

Web Services Scanner

Database Scanners

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Framework-based Fuzzer

Cost effective for partial coverage:

Fuzz Tester

Monitored Virtual Environment - run potentially malicious code in sandbox / wrapper / virtual machine, see if it does anything suspicious

Effectiveness: High

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Manual Source Code Review (not inspections)

Cost effective for partial coverage:

Focused Manual Spotcheck - Focused manual analysis of source

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Source code Weakness Analyzer

Context-configured Source Code Weakness Analyzer

Effectiveness: High

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	635	Weaknesses Originally Used by NVD from 2008 to 2016
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	743	CERT C Secure Coding Standard (2008) Chapter 10 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	751	2009 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	801	2010 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	852	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 9 - Visibility and Atomicity (VNA)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	867	2011 Top 25 - Weaknesses On the Cusp
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	877	CERT C++ Secure Coding Section 09 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	882	CERT C++ Secure Coding Section 14 - Concurrency (CON)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	988	SFP Secondary Cluster: Race Condition Window
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1142	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 08. Visibility and Atomicity (VNA)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1364	ICS Communications: Zone Boundary Failures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1365	ICS Communications: Unreliability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1366	ICS Communications: Frail Security in Protocols
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1376	ICS Engineering (Construction/Deployment): Security Gaps in Commissioning
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1387	Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1401	Comprehensive Categorization: Concurrency
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1425	Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses

Vulnerability Mapping Notes

Usage: ALLOWED-WITH-REVIEW

(this CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review)

Reason: Abstraction

Rationale:

This CWE entry is a Class and might have Base-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit

Notes

Research Gap

Race conditions in web applications are under-studied and probably under-reported. However, in 2008 there has been growing interest in this area.

Research Gap

Much of the focus of race condition research has been in Time-of-check Time-of-use (TOCTOU) variants (CWE-367), but many race conditions are related to synchronization problems that do not necessarily require a time-of-check.

Research Gap

From a classification/taxonomy perspective, the relationships between concurrency and program state need closer investigation and may be useful in organizing related issues.

Maintenance

The relationship between race conditions and synchronization problems (CWE-662) needs to be further developed. They are not necessarily two perspectives of the same core concept, since synchronization is only one technique for avoiding race conditions, and synchronization can be used for other purposes besides race condition prevention.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
PLOVER			Race Conditions
The CERT Oracle Secure Coding Standard for Java (2011)	VNA03-J		Do not assume that a group of calls to independently atomic methods is atomic

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-26	Leveraging Race Conditions
CAPEC-29	Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions

References

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 13: Race Conditions." Page 205. McGraw-Hill. 2010.

[REF-349] Andrei Alexandrescu. "volatile - Multithreaded Programmer's Best Friend". Dr. Dobb's. 2008-02-01. <https://drdobbs.com/cpp/volatile-the-multithreaded-programmers-b/184403766>. URL validated: 2023-04-07.

[REF-350] Steven Devijver. "Thread-safe webapps using Spring". <https://web.archive.org/web/20170609174845/http://www.javalobby.org/articles/thread-safe/index.jsp>. URL validated: 2023-04-07.

[REF-351] David Wheeler. "Prevent race conditions". 2007-10-04. <https://www.ida.liu.se/~TDDC90/literature/papers/SP-race-conditions.pdf>. URL validated: 2023-04-07.

[REF-352] Matt Bishop. "Race Conditions, Files, and Security Flaws; or the Tortoise and the Hare Redux". 1995-09. <https://seclab.cs.ucdavis.edu/projects/vulnerabilities/scriv/ucd-ecs-95-08.pdf>. URL validated: 2023-04-07.

[REF-353] David Wheeler. "Secure Programming for Linux and Unix HOWTO". 2003-03-03. <https://dwheeler.com/secure-programs/Secure-Programs-HOWTO/avoid-race.html>. URL validated: 2023-04-07.

[REF-354] Blake Watts. "Discovering and Exploiting Named Pipe Security Flaws for Fun and Profit". 2002-04. <https://www.blakewatts.com/blog/discovering-and-exploiting-named-pipe-security-flaws-for-fun-and-profit>. URL validated: 2023-04-07.

[REF-355] Roberto Paleari, Davide Marrone, Danilo Bruschi and Mattia Monga. "On Race Vulnerabilities in Web Applications". <http://security.dico.unimi.it/~roberto/pubs/dimva08-web.pdf>.

[REF-356] "Avoiding Race Conditions and Insecure File Operations". Apple Developer Connection. <https://web.archive.org/web/20081010155022/http://developer.apple.com/documentation/Security/Conceptual/SecureCodingGuide/Articles/RaceConditions.html>. URL validated: 2023-04-07.

[REF-357] Johannes Ullrich. "Top 25 Series - Rank 25 - Race Conditions". SANS Software Security Institute. 2010-03-26. <https://web.archive.org/web/20100530231203/http://blogs.sans.org:80/appsecstreetfighter/2010/03/26/top-25-series-rank-25-race-conditions/>. URL validated: 2023-04-07.

[REF-76] Sean Barnum and Michael Gegick. "Least Privilege". 2005-09-14. <https://web.archive.org/web/20211209014121/https://www.cisa.gov/uscert/bsi/articles/knowledge/principles/least-privilege>. URL validated: 2023-04-07.

[REF-1237] CERT Coordination Center. "Intel BIOS locking mechanism contains race condition that enables write protection bypass". 2015-01-05. <https://www.kb.cert.org/vuls/id/766164/>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	PLOVER
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2010-04-30	Martin Sebor	Cisco Systems, Inc.
2010-04-30	Provided Demonstrative Example
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships, Taxonomy_Mappings
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Relationships
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Relationships, Taxonomy_Mappings
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Description, Likelihood_of_Exploit, Maintenance_Notes, Observed_Examples, Potential_Mitigations, References, Relationships, Research_Gaps
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Demonstrative_Examples, Potential_Mitigations
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Relationships
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Detection_Factors, References, Relationships
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, Demonstrative_Examples, Detection_Factors, Potential_Mitigations, References
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Observed_Examples, Potential_Mitigations, Relationships
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Applicable_Platforms, Demonstrative_Examples, Description, Name, Potential_Mitigations, Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Potential_Mitigations, References, Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Detection_Factors, Relationships
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Demonstrative_Examples, References, Research_Gaps, Taxonomy_Mappings
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Demonstrative_Examples, Observed_Examples, Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Demonstrative_Examples
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Observed_Examples, References
2022-04-28	CWE Content Team	MITRE
2022-04-28	updated Observed_Examples, Relationships
2022-06-28	CWE Content Team	MITRE
2022-06-28	updated Observed_Examples, Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Observed_Examples, References
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Applicable_Platforms, Common_Consequences, Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
2024-07-16 (CWE 4.15, 2024-07-16)	CWE Content Team	MITRE
2024-07-16 (CWE 4.15, 2024-07-16)	updated Relationships
Previous Entry Names
Change Date	Previous Entry Name
2008-04-11	Race Conditions

2010-12-13	Race Condition

Weakness ID: 502

View customized information:

Description

The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.

Extended Description

It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions if it does not use cryptography to protect itself. Furthermore, any cryptography would still be client-side security -- which is a dangerous security assumption.

Data that is untrusted can not be trusted to be well-formed.

When developers place no restrictions on "gadget chains," or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.

Alternate Terms

Marshaling, Unmarshaling:	Marshaling and unmarshaling are effectively synonyms for serialization and deserialization, respectively.
Pickling, Unpickling:	In Python, the "pickle" functionality is used to perform serialization and deserialization.
PHP Object Injection:	Some PHP application researchers use this term when attacking unsafe use of the unserialize() function; but it is also used for CWE-915.

Common Consequences

Scope	Impact	Likelihood
Integrity	Technical Impact: Modify Application Data; Unexpected State Attackers can modify unexpected objects or data that was assumed to be safe from modification.
Availability	Technical Impact: DoS: Resource Consumption (CPU) If a function is making an assumption on when to terminate, based on a sentry in a string, it could easily never terminate.
Other	Technical Impact: Varies by Context The consequences can vary widely, because it depends on which objects or methods are being deserialized, and how they are used. Making an assumption that the code in the deserialized object is valid is dangerous and can enable exploitation.

Potential Mitigations

Phases: Architecture and Design; Implementation

If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.

Phase: Implementation

When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.

Phase: Implementation

Explicitly define a final object() to prevent deserialization.

Phases: Architecture and Design; Implementation

Make fields transient to protect them from deserialization.

An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

Phase: Implementation

Avoid having unnecessary types or gadgets available that can be leveraged for malicious ends. This limits the potential for unintended or unauthorized types and gadgets to be leveraged by the attacker. Add only acceptable classes to an allowlist. Note: new gadgets are constantly being discovered, so this alone is not a sufficient mitigation.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	913	Improper Control of Dynamically-Managed Code Resources
PeerOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	915	Improperly Controlled Modification of Dynamically-Determined Object Attributes

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	399	Resource Management Errors

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	913	Improper Control of Dynamically-Managed Code Resources

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1019	Validate Inputs

Background Details

Serialization and deserialization refer to the process of taking program-internal object-related data, packaging it in a way that allows the data to be externally stored or transferred ("serialization"), then extracting the serialized data to reconstruct the original object ("deserialization").

Modes Of Introduction

Phase	Note
Architecture and Design	OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Implementation

Applicable Platforms

Languages

Java (Undetermined Prevalence)

Ruby (Undetermined Prevalence)

PHP (Undetermined Prevalence)

Python (Undetermined Prevalence)

JavaScript (Undetermined Prevalence)

Technologies

Class: ICS/OT (Often Prevalent)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

This code snippet deserializes an object from a file and uses it as a UI button:

(bad code)

Example Language: Java

try {

File file = new File("object.obj");
ObjectInputStream in = new ObjectInputStream(new FileInputStream(file));
javax.swing.JButton button = (javax.swing.JButton) in.readObject();
in.close();

}

This code does not attempt to verify the source or contents of the file before deserializing it. An attacker may be able to replace the intended file with a file that contains arbitrary malicious code which will be executed when the button is pressed.

To mitigate this, explicitly define final readObject() to prevent deserialization. An example of this is:

(good code)

Example Language: Java

private final void readObject(ObjectInputStream in) throws java.io.IOException {
throw new java.io.IOException("Cannot be deserialized"); }

Example 2

In Python, the Pickle library handles the serialization and deserialization processes. In this example derived from [REF-467], the code receives and parses data, and afterwards tries to authenticate a user based on validating a token.

(bad code)

Example Language: Python

try {

class ExampleProtocol(protocol.Protocol):
def dataReceived(self, data):

# Code that would be here would parse the incoming data
# After receiving headers, call confirmAuth() to authenticate

def confirmAuth(self, headers):
try:
token = cPickle.loads(base64.b64decode(headers['AuthToken']))
if not check_hmac(token['signature'], token['data'], getSecretKey()):
raise AuthFail
self.secure_data = token['data']
except:
raise AuthFail

}

Unfortunately, the code does not verify that the incoming data is legitimate. An attacker can construct a illegitimate, serialized object "AuthToken" that instantiates one of Python's subprocesses to execute arbitrary commands. For instance,the attacker could construct a pickle that leverages Python's subprocess module, which spawns new processes and includes a number of arguments for various uses. Since Pickle allows objects to define the process for how they should be unpickled, the attacker can direct the unpickle process to call Popen in the subprocess module and execute /bin/sh.

Observed Examples

Reference	Description
CVE-2019-12799	chain: bypass of untrusted deserialization issue (CWE-502) by using an assumed-trusted class (CWE-183)
CVE-2015-8103	Deserialization issue in commonly-used Java library allows remote execution.
CVE-2015-4852	Deserialization issue in commonly-used Java library allows remote execution.
CVE-2013-1465	Use of PHP unserialize function on untrusted input allows attacker to modify application configuration.
CVE-2012-3527	Use of PHP unserialize function on untrusted input in content management system might allow code execution.
CVE-2012-0911	Use of PHP unserialize function on untrusted input in content management system allows code execution using a crafted cookie value.
CVE-2012-0911	Content management system written in PHP allows unserialize of arbitrary objects, possibly allowing code execution.
CVE-2011-2520	Python script allows local users to execute code via pickled data.
CVE-2012-4406	Unsafe deserialization using pickle in a Python script.
CVE-2003-0791	Web browser allows execution of native methods via a crafted string to a JavaScript function that deserializes the string.

Detection Methods

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	858	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	994	SFP Secondary Cluster: Tainted Input to Variable
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1034	OWASP Top Ten 2017 Category A8 - Insecure Deserialization
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1148	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 14. Serialization (SER)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1200	Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1337	Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1350	Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1354	OWASP Top Ten 2021 Category A08:2021 - Software and Data Integrity Failures
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1387	Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1415	Comprehensive Categorization: Resource Control
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1425	Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Maintenance

The relationships between CWE-502 and CWE-915 need further exploration. CWE-915 is more narrowly scoped to object modification, and is not necessarily used for deserialization.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
CLASP		Deserialization of untrusted data
The CERT Oracle Secure Coding Standard for Java (2011)	SER01-J	Do not deviate from the proper signatures of serialization methods
The CERT Oracle Secure Coding Standard for Java (2011)	SER03-J	Do not serialize unencrypted, sensitive data
The CERT Oracle Secure Coding Standard for Java (2011)	SER06-J	Make defensive copies of private mutable components during deserialization
The CERT Oracle Secure Coding Standard for Java (2011)	SER08-J	Do not use the default serialized form for implementation defined invariants
Software Fault Patterns	SFP25	Tainted input to variable

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-586	Object Injection

References

[REF-18] Secure Software, Inc.. "The CLASP Application Security Process". 2005. <https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf>.

[REF-461] Matthias Kaiser. "Exploiting Deserialization Vulnerabilities in Java". 2015-10-28. <https://www.slideshare.net/codewhitesec/exploiting-deserialization-vulnerabilities-in-java-54707478>. URL validated: 2023-04-07.

[REF-462] Sam Thomas. "PHP unserialization vulnerabilities: What are we missing?". 2015-08-27. <https://www.slideshare.net/_s_n_t/php-unserialization-vulnerabilities-what-are-we-missing>. URL validated: 2023-04-07.

[REF-463] Gabriel Lawrence and Chris Frohoff. "Marshalling Pickles: How deserializing objects can ruin your day". 2015-01-28. <https://www.slideshare.net/frohoff1/appseccali-2015-marshalling-pickles>. URL validated: 2023-04-07.

[REF-464] Heine Deelstra. "Unserializing user-supplied data, a bad idea". 2010-08-25. <https://drupalsun.com/heine/2010/08/25/unserializing-user-supplied-data-bad-idea>. URL validated: 2023-04-07.

[REF-465] Manish S. Saindane. "Black Hat EU 2010 - Attacking Java Serialized Communication". 2010-04-26. <https://www.slideshare.net/msaindane/black-hat-eu-2010-attacking-java-serialized-communication>. URL validated: 2023-04-07.

[REF-466] Nadia Alramli. "Why Python Pickle is Insecure". 2009-09-09. <http://michael-rushanan.blogspot.com/2012/10/why-python-pickle-is-insecure.html>. URL validated: 2023-04-07.

[REF-467] Nelson Elhage. "Exploiting misuse of Python's "pickle"". 2011-03-20. <https://blog.nelhage.com/2011/03/exploiting-pickle/>.

[REF-468] Chris Frohoff. "Deserialize My Shorts: Or How I Learned to Start Worrying and Hate Java Object Deserialization". 2016-03-21. <https://speakerdeck.com/frohoff/owasp-sd-deserialize-my-shorts-or-how-i-learned-to-start-worrying-and-hate-java-object-deserialization>. URL validated: 2023-04-07.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	CLASP
2006-07-19 (CWE Draft 3, 2006-07-19)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Common_Consequences, Description, Relationships, Other_Notes, Taxonomy_Mappings
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Description, Other_Notes, Potential_Mitigations
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Demonstrative_Examples
2013-02-21	CWE Content Team	MITRE
2013-02-21	updated Alternate_Terms, Applicable_Platforms, Background_Details, Common_Consequences, Maintenance_Notes, Observed_Examples, Potential_Mitigations, References, Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Observed_Examples, References, Relationships
2017-05-03	CWE Content Team	MITRE
2017-05-03	updated Applicable_Platforms, Demonstrative_Examples, Description, Potential_Mitigations, References
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Modes_of_Introduction, Potential_Mitigations, References, Relationships
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated Relationships
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Type
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Observed_Examples, References, Relationships
2020-06-25	CWE Content Team	MITRE
2020-06-25	updated Alternate_Terms, Potential_Mitigations
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-06-28	CWE Content Team	MITRE
2022-06-28	updated Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Applicable_Platforms
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships

Weakness ID: 494

View customized information:

Description

The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.

Extended Description

An attacker can execute malicious code by compromising the host server, performing DNS spoofing, or modifying the code in transit.

Common Consequences

Scope	Impact	Likelihood
Integrity Availability Confidentiality Other	Technical Impact: Execute Unauthorized Code or Commands; Alter Execution Logic; Other Executing untrusted code could compromise the control flow of the program. The untrusted code could execute attacker-controlled commands, read or modify sensitive resources, or prevent the software from functioning correctly for legitimate users.

Potential Mitigations

Phase: Implementation

Perform proper forward and reverse DNS lookups to detect DNS spoofing.

Note: This is only a partial solution since it will not prevent your code from being modified on the hosting site or in transit.

Phases: Architecture and Design; Operation

Encrypt the code with a reliable encryption scheme before transmitting.

This will only be a partial solution, since it will not detect DNS spoofing and it will not prevent your code from being modified on the hosting site.

Phase: Architecture and Design

Strategy: Libraries or Frameworks

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

Speficially, it may be helpful to use tools or frameworks to perform integrity checking on the transmitted code.

When providing the code that is to be downloaded, such as for automatic updates of the software, then use cryptographic signatures for the code and modify the download clients to verify the signatures. Ensure that the implementation does not contain CWE-295, CWE-320, CWE-347, and related weaknesses.

Use code signing technologies such as Authenticode. See references [REF-454] [REF-455] [REF-456].

Phases: Architecture and Design; Operation

Strategy: Environment Hardening

Phases: Architecture and Design; Operation

Strategy: Sandbox or Jail

Run the code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.

OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.

This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.

Be careful to avoid CWE-243 and other weaknesses related to jails.

Effectiveness: Limited

Note: The effectiveness of this mitigation depends on the prevention capabilities of the specific sandbox or jail being used and might only help to reduce the scope of an attack, such as restricting the attacker to certain system calls or limiting the portion of the file system that can be accessed.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	669	Incorrect Resource Transfer Between Spheres
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	345	Insufficient Verification of Data Authenticity
CanFollow	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	79	Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1214	Data Integrity Issues

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	669	Incorrect Resource Transfer Between Spheres

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1020	Verify Message Integrity

Modes Of Introduction

Phase	Note
Architecture and Design	OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Implementation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

This example loads an external class from a local subdirectory.

(bad code)

Example Language: Java

URL[] classURLs= new URL[]{

new URL("file:subdir/")

};
URLClassLoader loader = new URLClassLoader(classURLs);
Class loadedClass = Class.forName("loadMe", true, loader);

This code does not ensure that the class loaded is the intended one, for example by verifying the class's checksum. An attacker may be able to modify the class file to execute malicious code.

Example 2

This code includes an external script to get database credentials, then authenticates a user against the database, allowing access to the application.

(bad code)

Example Language: PHP

//assume the password is already encrypted, avoiding CWE-312

function authenticate($username,$password){

include("http://external.example.com/dbInfo.php");

//dbInfo.php makes $dbhost, $dbuser, $dbpass, $dbname available
mysql_connect($dbhost, $dbuser, $dbpass) or die ('Error connecting to mysql');
mysql_select_db($dbname);
$query = 'Select * from users where username='.$username.' And password='.$password;
$result = mysql_query($query);

if(mysql_numrows($result) == 1){

mysql_close();
return true;

}
else{

mysql_close();
return false;

}

This code does not verify that the external domain accessed is the intended one. An attacker may somehow cause the external domain name to resolve to an attack server, which would provide the information for a false database. The attacker may then steal the usernames and encrypted passwords from real user login attempts, or simply allow themself to access the application without a real user account.

This example is also vulnerable to an Adversary-in-the-Middle AITM (CWE-300) attack.

Observed Examples

Reference	Description
CVE-2019-9534	Satellite phone does not validate its firmware image.
CVE-2021-22909	Chain: router's firmware update procedure uses curl with "-k" (insecure) option that disables certificate validation (CWE-295), allowing adversary-in-the-middle (AITM) compromise with a malicious firmware image (CWE-494).
CVE-2008-3438	OS does not verify authenticity of its own updates.
CVE-2008-3324	online poker client does not verify authenticity of its own updates.
CVE-2001-1125	anti-virus product does not verify automatic updates for itself.
CVE-2002-0671	VOIP phone downloads applications from web sites without verifying integrity.

Detection Methods

Manual Analysis

This weakness can be detected using tools and techniques that require manual (human) analysis, such as penetration testing, threat modeling, and interactive tools that allow the tester to record and modify an active session.

Specifically, manual static analysis is typically required to find the behavior that triggers the download of code, and to determine whether integrity-checking methods are in use.

Note: These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Black Box

Attach the monitor to the process and also sniff the network connection. Trigger features related to product updates or plugin installation, which is likely to force a code download. Monitor when files are downloaded and separately executed, or if they are otherwise read back into the process. Look for evidence of cryptographic library calls that use integrity checking.

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	752	2009 Top 25 - Risky Resource Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	802	2010 Top 25 - Risky Resource Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	859	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 16 - Platform Security (SEC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	865	2011 Top 25 - Risky Resource Management
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	991	SFP Secondary Cluster: Tainted Input to Environment
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1354	OWASP Top Ten 2021 Category A08:2021 - Software and Data Integrity Failures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1364	ICS Communications: Zone Boundary Failures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1411	Comprehensive Categorization: Insufficient Verification of Data Authenticity

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Research Gap

This is critical for mobile code, but it is likely to become more and more common as developers continue to adopt automated, network-based product distributions and upgrades. Software-as-a-Service (SaaS) might introduce additional subtleties. Common exploitation scenarios may include ad server compromises and bad upgrades.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
CLASP		Invoking untrusted mobile code
The CERT Oracle Secure Coding Standard for Java (2011)	SEC06-J	Do not rely on the default automatic signature verification provided by URLClassLoader and java.util.jar
Software Fault Patterns	SFP27	Tainted input to environment

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-184	Software Integrity Attack
CAPEC-185	Malicious Software Download
CAPEC-186	Malicious Software Update
CAPEC-187	Malicious Automated Software Update via Redirection
CAPEC-533	Malicious Manual Software Update
CAPEC-538	Open-Source Library Manipulation
CAPEC-657	Malicious Automated Software Update via Spoofing
CAPEC-662	Adversary in the Browser (AiTB)
CAPEC-691	Spoof Open-Source Software Metadata
CAPEC-692	Spoof Version Control System Commit Metadata
CAPEC-693	StarJacking
CAPEC-695	Repo Jacking

References

[REF-454] Microsoft. "Introduction to Code Signing". <http://msdn.microsoft.com/en-us/library/ms537361(VS.85).aspx>.

[REF-455] Microsoft. "Authenticode". <http://msdn.microsoft.com/en-us/library/ms537359(v=VS.85).aspx>.

[REF-456] Apple. "Code Signing Guide". Apple Developer Connection. 2008-11-19. <https://web.archive.org/web/20080724215143/http://developer.apple.com/documentation/Security/Conceptual/CodeSigningGuide/Introduction/chapter_1_section_1.html>. URL validated: 2023-04-07.

[REF-457] Anthony Bellissimo, John Burgess and Kevin Fu. "Secure Software Updates: Disappointments and New Challenges". <http://prisms.cs.umass.edu/~kevinfu/papers/secureupdates-hotsec06.pdf>.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 18: The Sins of Mobile Code." Page 267. McGraw-Hill. 2010.

[REF-459] Johannes Ullrich. "Top 25 Series - Rank 20 - Download of Code Without Integrity Check". SANS Software Security Institute. 2010-04-05. <https://www.sans.org/blog/top-25-series-rank-20-download-of-code-without-integrity-check/>. URL validated: 2023-04-07.

[REF-18] Secure Software, Inc.. "The CLASP Application Security Process". 2005. <https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	CLASP
2006-07-19 (CWE Draft 3, 2006-07-19)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships, Other_Notes, Taxonomy_Mappings
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Applicable_Platforms, Common_Consequences, Description, Name, Other_Notes, Potential_Mitigations, References, Relationships, Research_Gaps, Type
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Description, Observed_Examples, Related_Attack_Patterns
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Detection_Factors, References, Relationships
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Applicable_Platforms
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, Detection_Factors, Potential_Mitigations, References
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Potential_Mitigations, References
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Potential_Mitigations
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Demonstrative_Examples
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, References
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated References, Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Modes_of_Introduction, References, Relationships
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Related_Attack_Patterns, Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Demonstrative_Examples, Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Demonstrative_Examples
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated References, Related_Attack_Patterns
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Demonstrative_Examples
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Observed_Examples, Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated References, Related_Attack_Patterns
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Related_Attack_Patterns
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Demonstrative_Examples, Relationships
Previous Entry Names
Change Date	Previous Entry Name
2008-04-11	Mobile Code: Invoking Untrusted Mobile Code

2009-01-12	Download of Untrusted Mobile Code Without Integrity Check

Weakness ID: 250

View customized information:

Description

The product performs an operation at a privilege level that is higher than the minimum level required, which creates new weaknesses or amplifies the consequences of other weaknesses.

Extended Description

New weaknesses can be exposed because running with extra privileges, such as root or Administrator, can disable the normal security checks being performed by the operating system or surrounding environment. Other pre-existing weaknesses can turn into security vulnerabilities if they occur while operating at raised privileges.

Privilege management functions can behave in some less-than-obvious ways, and they have different quirks on different platforms. These inconsistencies are particularly pronounced if you are transitioning from one non-root user to another. Signal handlers and spawned processes run at the privilege of the owning process, so if a process is running as root when a signal fires or a sub-process is executed, the signal handler or sub-process will operate with root privileges.

Common Consequences

Scope	Impact	Likelihood
Confidentiality Integrity Availability Access Control	Technical Impact: Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands; Read Application Data; DoS: Crash, Exit, or Restart An attacker will be able to gain access to any resources that are allowed by the extra privileges. Common results include executing code, disabling services, and reading restricted data.

Potential Mitigations

Phases: Architecture and Design; Operation

Strategy: Environment Hardening

Phase: Architecture and Design

Strategy: Separation of Privilege

Identify the functionality that requires additional privileges, such as access to privileged operating system resources. Wrap and centralize this functionality if possible, and isolate the privileged code as much as possible from other code [REF-76]. Raise privileges as late as possible, and drop them as soon as possible to avoid CWE-271. Avoid weaknesses such as CWE-288 and CWE-420 by protecting all possible communication channels that could interact with the privileged code, such as a secondary socket that is only intended to be accessed by administrators.

Phase: Architecture and Design

Strategy: Attack Surface Reduction

Phase: Implementation

Perform extensive input validation for any privileged code that must be exposed to the user and reject anything that does not fit your strict requirements.

Phase: Implementation

When dropping privileges, ensure that they have been dropped successfully to avoid CWE-273. As protection mechanisms in the environment get stronger, privilege-dropping calls may fail even if it seems like they would always succeed.

Phase: Implementation

If circumstances force you to run with extra privileges, then determine the minimum access level necessary. First identify the different permissions that the software and its users will need to perform their actions, such as file read and write permissions, network socket permissions, and so forth. Then explicitly allow those actions while denying all else [REF-76]. Perform extensive input validation and canonicalization to minimize the chances of introducing a separate vulnerability. This mitigation is much more prone to error than dropping the privileges in the first place.

Phases: Operation; System Configuration

Strategy: Environment Hardening

Ensure that the software runs properly under the United States Government Configuration Baseline (USGCB) [REF-199] or an equivalent hardening configuration guide, which many organizations use to limit the attack surface and potential risk of deployed software.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	657	Violation of Secure Design Principles
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	269	Improper Privilege Management

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	265	Privilege Issues

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1015	Limit Access

Modes Of Introduction

Phase	Note
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic.
Installation
Architecture and Design	If an application has this design problem, then it can be easier for the developer to make implementation-related errors such as CWE-271 (Privilege Dropping / Lowering Errors). In addition, the consequences of Privilege Chaining (CWE-268) can become more severe.
Operation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: Mobile (Undetermined Prevalence)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

This code temporarily raises the program's privileges to allow creation of a new user folder.

(bad code)

Example Language: Python

def makeNewUserDir(username):

if invalidUsername(username):

#avoid CWE-22 and CWE-78
print('Usernames cannot contain invalid characters')
return False

try:

raisePrivileges()
os.mkdir('/home/' + username)
lowerPrivileges()

except OSError:

print('Unable to create new user directory for user:' + username)
return False

return True

While the program only raises its privilege level to create the folder and immediately lowers it again, if the call to os.mkdir() throws an exception, the call to lowerPrivileges() will not occur. As a result, the program is indefinitely operating in a raised privilege state, possibly allowing further exploitation to occur.

Example 2

The following code calls chroot() to restrict the application to a subset of the filesystem below APP_HOME in order to prevent an attacker from using the program to gain unauthorized access to files located elsewhere. The code then opens a file specified by the user and processes the contents of the file.

(bad code)

Example Language: C

chroot(APP_HOME);
chdir("/");
FILE* data = fopen(argv[1], "r+");
...

Constraining the process inside the application's home directory before opening any files is a valuable security measure. However, the absence of a call to setuid() with some non-zero value means the application is continuing to operate with unnecessary root privileges. Any successful exploit carried out by an attacker against the application can now result in a privilege escalation attack because any malicious operations will be performed with the privileges of the superuser. If the application drops to the privilege level of a non-root user, the potential for damage is substantially reduced.

Example 3

This application intends to use a user's location to determine the timezone the user is in:

(bad code)

Example Language: Java

locationClient = new LocationClient(this, this, this);
locationClient.connect();
Location userCurrLocation;
userCurrLocation = locationClient.getLastLocation();
setTimeZone(userCurrLocation);

This is unnecessary use of the location API, as this information is already available using the Android Time API. Always be sure there is not another way to obtain needed information before resorting to using the location API.

Example 4

This code uses location to determine the user's current US State location.

First the application must declare that it requires the ACCESS_FINE_LOCATION permission in the application's manifest.xml:

(bad code)

Example Language: XML

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

During execution, a call to getLastLocation() will return a location based on the application's location permissions. In this case the application has permission for the most accurate location possible:

(bad code)

Example Language: Java

locationClient = new LocationClient(this, this, this);
locationClient.connect();
Location userCurrLocation;
userCurrLocation = locationClient.getLastLocation();
deriveStateFromCoords(userCurrLocation);

While the application needs this information, it does not need to use the ACCESS_FINE_LOCATION permission, as the ACCESS_COARSE_LOCATION permission will be sufficient to identify which US state the user is in.

Observed Examples

Reference	Description
CVE-2007-4217	FTP client program on a certain OS runs with setuid privileges and has a buffer overflow. Most clients do not need extra privileges, so an overflow is not a vulnerability for those clients.
CVE-2008-1877	Program runs with privileges and calls another program with the same privileges, which allows read of arbitrary files.
CVE-2007-5159	OS incorrectly installs a program with setuid privileges, allowing users to gain privileges.
CVE-2008-4638	Composite: application running with high privileges (CWE-250) allows user to specify a restricted file to process, which generates a parsing error that leaks the contents of the file (CWE-209).
CVE-2008-0162	Program does not drop privileges before calling another program, allowing code execution.
CVE-2008-0368	setuid root program allows creation of arbitrary files through command line argument.
CVE-2007-3931	Installation script installs some programs as setuid when they shouldn't be.
CVE-2020-3812	mail program runs as root but does not drop its privileges before attempting to access a file. Attacker can use a symlink from their home directory to a directory only readable by root, then determine whether the file exists based on the response.
CVE-2003-0908	Product launches Help functionality while running with raised privileges, allowing command execution using Windows message to access "open file" dialog.

Detection Methods

Manual Analysis

Note: These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Black Box

Attach the monitor to the process and perform a login. Look for library functions and system calls that indicate when privileges are being raised or dropped. Look for accesses of resources that are restricted to normal users.

Note: Note that this technique is only useful for privilege issues related to system resources. It is not likely to detect application-level business rules that are related to privileges, such as if a blog system allows a user to delete a blog entry without first checking that the user has administrator privileges.

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Compare binary / bytecode to application permission manifest

Cost effective for partial coverage:

Bytecode Weakness Analysis - including disassembler + source code weakness analysis

Binary Weakness Analysis - including disassembler + source code weakness analysis

Effectiveness: High

Manual Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Host-based Vulnerability Scanners - Examine configuration for flaws, verifying that audit mechanisms work, ensure host configuration meets certain predefined criteria

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Host Application Interface Scanner

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Manual Source Code Review (not inspections)

Cost effective for partial coverage:

Focused Manual Spotcheck - Focused manual analysis of source

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Source code Weakness Analyzer

Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Automated Static Analysis

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Configuration Checker

Permission Manifest Analysis

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Attack Modeling

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	227	7PK - API Abuse
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	753	2009 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	815	OWASP Top Ten 2010 Category A6 - Security Misconfiguration
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	858	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	866	2011 Top 25 - Porous Defenses
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	901	SFP Primary Cluster: Privilege
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1418	Comprehensive Categorization: Violation of Secure Design Principles

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Relationship

There is a close association with CWE-653 (Insufficient Separation of Privileges). CWE-653 is about providing separate components for each privilege; CWE-250 is about ensuring that each component has the least amount of privileges possible.

Maintenance

CWE-271, CWE-272, and CWE-250 are all closely related and possibly overlapping. CWE-271 is probably better suited as a category. Both CWE-272 and CWE-250 are in active use by the community. The "least privilege" phrase has multiple interpretations.

Maintenance

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
7 Pernicious Kingdoms		Often Misused: Privilege Management
The CERT Oracle Secure Coding Standard for Java (2011)	SER09-J	Minimize privileges before deserializing from a privilege context
ISA/IEC 62443	Part 2-4	Req SP.03.05 BR
ISA/IEC 62443	Part 2-4	Req SP.03.08 BR
ISA/IEC 62443	Part 2-4	Req SP.03.08 RE(1)
ISA/IEC 62443	Part 2-4	Req SP.05.07 BR
ISA/IEC 62443	Part 2-4	Req SP.09.02 RE(4)
ISA/IEC 62443	Part 2-4	Req SP.09.03 BR
ISA/IEC 62443	Part 2-4	Req SP.09.04 BR
ISA/IEC 62443	Part 3-3	Req SR 1.1
ISA/IEC 62443	Part 3-3	Req SR 1.2
ISA/IEC 62443	Part 3-3	Req SR 2.1
ISA/IEC 62443	Part 3-3	Req SR 2.1 RE 1
ISA/IEC 62443	Part 4-1	Req SD-4
ISA/IEC 62443	Part 4-2	Req CCSC 3
ISA/IEC 62443	Part 4-2	Req CR 1.1

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-104	Cross Zone Scripting
CAPEC-470	Expanding Control over the Operating System from the Database
CAPEC-69	Target Programs with Elevated Privileges

References

[REF-6] Katrina Tsipenyuk, Brian Chess and Gary McGraw. "Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors". NIST Workshop on Software Security Assurance Tools Techniques and Metrics. NIST. 2005-11-07. <https://samate.nist.gov/SSATTM_Content/papers/Seven%20Pernicious%20Kingdoms%20-%20Taxonomy%20of%20Sw%20Security%20Errors%20-%20Tsipenyuk%20-%20Chess%20-%20McGraw.pdf>.

[REF-196] Jerome H. Saltzer and Michael D. Schroeder. "The Protection of Information in Computer Systems". Proceedings of the IEEE 63. 1975-09. <http://web.mit.edu/Saltzer/www/publications/protection/>.

[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 7, "Running with Least Privilege" Page 207. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.

[REF-199] NIST. "United States Government Configuration Baseline (USGCB)". <https://csrc.nist.gov/Projects/United-States-Government-Configuration-Baseline>. URL validated: 2023-03-28.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 16: Executing Code With Too Much Privilege." Page 243. McGraw-Hill. 2010.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 9, "Privilege Vulnerabilities", Page 477. 1st Edition. Addison Wesley. 2006.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	7 Pernicious Kingdoms
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2023-01-24 (CWE 4.10, 2023-01-31)	"Mapping CWE to 62443" Sub-Working Group	CWE-CAPEC ICS/OT SIG
2023-01-24 (CWE 4.10, 2023-01-31)	Suggested mappings to ISA/IEC 62443.
2023-04-25	"Mapping CWE to 62443" Sub-Working Group	CWE-CAPEC ICS/OT SIG
2023-04-25	Suggested mappings to ISA/IEC 62443.
Modifications
Modification Date	Modifier	Organization
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Description, Modes_of_Introduction, Relationships, Other_Notes, Relationship_Notes, Taxonomy_Mappings
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Description, Maintenance_Notes
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Common_Consequences, Description, Likelihood_of_Exploit, Maintenance_Notes, Name, Observed_Examples, Other_Notes, Potential_Mitigations, Relationships, Time_of_Introduction
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Related_Attack_Patterns
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Detection_Factors, Potential_Mitigations, References
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Detection_Factors, Potential_Mitigations
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Demonstrative_Examples, Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, References, Relationships
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated References, Related_Attack_Patterns, Relationships
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2013-07-17	CWE Content Team	MITRE
2013-07-17	updated Applicable_Platforms
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Demonstrative_Examples
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Detection_Factors
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Modes_of_Introduction, References, Relationships
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Taxonomy_Mappings
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Demonstrative_Examples
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Detection_Factors, Observed_Examples, References, Relationships, Type
2022-04-28	CWE Content Team	MITRE
2022-04-28	updated Observed_Examples
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated References
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description, Maintenance_Notes, Taxonomy_Mappings
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2023-10-26	CWE Content Team	MITRE
2023-10-26	updated Observed_Examples
Previous Entry Names
Change Date	Previous Entry Name
2008-01-30	Often Misused: Privilege Management

2009-01-12	Design Principle Violation: Failure to Use Least Privilege

Weakness ID: 359

View customized information:

Description

Extended Description

There are many types of sensitive information that products must protect from attackers, including system data, communications, configuration, business secrets, intellectual property, and an individual's personal (private) information. Private personal information may include a password, phone number, geographic location, personal messages, credit card number, etc. Private information is important to consider whether the person is a user of the product, or part of a data set that is processed by the product. An exposure of private information does not necessarily prevent the product from working properly, and in fact the exposure might be intended by the developer, e.g. as part of data sharing with other organizations. However, the exposure of personal private information can still be undesirable or explicitly prohibited by law or regulation.

Some types of private information include:

Government identifiers, such as Social Security Numbers
Contact information, such as home addresses and telephone numbers
Geographic location - where the user is (or was)
Employment history
Financial data - such as credit card numbers, salary, bank accounts, and debts
Pictures, video, or audio
Behavioral patterns - such as web surfing history, when certain activities are performed, etc.
Relationships (and types of relationships) with others - family, friends, contacts, etc.
Communications - e-mail addresses, private messages, text messages, chat logs, etc.
Health - medical conditions, insurance status, prescription records
Account passwords and other credentials

Some of this information may be characterized as PII (Personally Identifiable Information), Protected Health Information (PHI), etc. Categories of private information may overlap or vary based on the intended usage or the policies and practices of a particular industry.

Sometimes data that is not labeled as private can have a privacy implication in a different context. For example, student identification numbers are usually not considered private because there is no explicit and publicly-available mapping to an individual student's personal information. However, if a school generates identification numbers based on student social security numbers, then the identification numbers should be considered private.

Alternate Terms

Privacy violation
Privacy leak
Privacy leakage

Common Consequences

Scope	Impact	Likelihood
Confidentiality	Technical Impact: Read Application Data

Potential Mitigations

Phase: Requirements

Identify and consult all relevant regulations for personal privacy. An organization may be required to comply with certain federal and state regulations, depending on its location, the type of business it conducts, and the nature of any private data it handles. Regulations may include Safe Harbor Privacy Framework [REF-340], Gramm-Leach Bliley Act (GLBA) [REF-341], Health Insurance Portability and Accountability Act (HIPAA) [REF-342], General Data Protection Regulation (GDPR) [REF-1047], California Consumer Privacy Act (CCPA) [REF-1048], and others.

Phase: Architecture and Design

Carefully evaluate how secure design may interfere with privacy, and vice versa. Security and privacy concerns often seem to compete with each other. From a security perspective, all important operations should be recorded so that any anomalous activity can later be identified. However, when private data is involved, this practice can in fact create risk. Although there are many ways in which private data can be handled unsafely, a common risk stems from misplaced trust. Programmers often trust the operating environment in which a program runs, and therefore believe that it is acceptable store private information on the file system, in the registry, or in other locally-controlled resources. However, even if access to certain resources is restricted, this does not guarantee that the individuals who do have access can be trusted.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	200	Exposure of Sensitive Information to an Unauthorized Actor

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	199	Information Management Errors

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1011	Authorize Actors

Modes Of Introduction

Phase	Note
Architecture and Design	OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Implementation
Operation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: Mobile (Undetermined Prevalence)

Demonstrative Examples

Example 1

The following code contains a logging statement that tracks the contents of records added to a database by storing them in a log file. Among other values that are stored, the getPassword() function returns the user-supplied plaintext password associated with the account.

(bad code)

Example Language: C#

pass = GetPassword();
...
dbmsLog.WriteLine(id + ":" + pass + ":" + type + ":" + tstamp);

The code in the example above logs a plaintext password to the filesystem. Although many developers trust the filesystem as a safe storage location for data, it should not be trusted implicitly, particularly when privacy is a concern.

Example 2

This code uses location to determine the user's current US State location.

First the application must declare that it requires the ACCESS_FINE_LOCATION permission in the application's manifest.xml:

(bad code)

Example Language: XML

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

(bad code)

Example Language: Java

Example 3

In 2004, an employee at AOL sold approximately 92 million private customer e-mail addresses to a spammer marketing an offshore gambling web site [REF-338]. In response to such high-profile exploits, the collection and management of private data is becoming increasingly regulated.

Detection Methods

Architecture or Design Review

Private personal data can enter a program in a variety of ways:

Directly from the user in the form of a password or personal information

Accessed from a database or other data store by the application

Indirectly from a partner or other third party

If the data is written to an external location - such as the console, file system, or network - a privacy violation may occur.

Effectiveness: High

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	254	7PK - Security Features
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	857	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	975	SFP Secondary Cluster: Architecture
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1029	OWASP Top Ten 2017 Category A3 - Sensitive Data Exposure
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1147	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 13. Input Output (FIO)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1345	OWASP Top Ten 2021 Category A01:2021 - Broken Access Control
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1417	Comprehensive Categorization: Sensitive Information Exposure

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Maintenance

This entry overlaps many other entries that are not organized around the kind of sensitive information that is exposed. However, because privacy is treated with such importance due to regulations and other factors, and it may be useful for weakness-finding tools to highlight capabilities that detect personal private information instead of system information, it is not clear whether - and how - this entry should be deprecated.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
7 Pernicious Kingdoms			Privacy Violation
The CERT Oracle Secure Coding Standard for Java (2011)	FIO13-J		Do not log sensitive information outside a trust boundary

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-464	Evercookie
CAPEC-467	Cross Site Identification
CAPEC-498	Probe iOS Screenshots
CAPEC-508	Shoulder Surfing

References

[REF-338] J. Oates. "AOL man pleads guilty to selling 92m email addies". The Register. 2005. <https://www.theregister.com/2005/02/07/aol_email_theft/>. URL validated: 2023-04-07.

[REF-339] NIST. "Guide to Protecting the Confidentiality of Personally Identifiable Information (SP 800-122)". 2010-04. <https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-122.pdf>. URL validated: 2023-04-07.

[REF-340] U.S. Department of Commerce. "Safe Harbor Privacy Framework". <https://web.archive.org/web/20010223203241/http://www.export.gov/safeharbor/>. URL validated: 2023-04-07.

[REF-341] Federal Trade Commission. "Financial Privacy: The Gramm-Leach Bliley Act (GLBA)". <https://www.ftc.gov/business-guidance/privacy-security/gramm-leach-bliley-act>. URL validated: 2023-04-07.

[REF-342] U.S. Department of Human Services. "Health Insurance Portability and Accountability Act (HIPAA)". <https://www.hhs.gov/hipaa/index.html>. URL validated: 2023-04-07.

[REF-343] Government of the State of California. "California SB-1386". 2002. <http://info.sen.ca.gov/pub/01-02/bill/sen/sb_1351-1400/sb_1386_bill_20020926_chaptered.html>.

[REF-267] Information Technology Laboratory, National Institute of Standards and Technology. "SECURITY REQUIREMENTS FOR CRYPTOGRAPHIC MODULES". 2001-05-25. <https://csrc.nist.gov/csrc/media/publications/fips/140/2/final/documents/fips1402.pdf>. URL validated: 2023-04-07.

[REF-172] Chris Wysopal. "Mobile App Top 10 List". 2010-12-13. <https://www.veracode.com/blog/2010/12/mobile-app-top-10-list>. URL validated: 2023-04-07.

[REF-1047] Wikipedia. "General Data Protection Regulation". <https://en.wikipedia.org/wiki/General_Data_Protection_Regulation>.

[REF-1048] State of California Department of Justice, Office of the Attorney General. "California Consumer Privacy Act (CCPA)". <https://oag.ca.gov/privacy/ccpa>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	7 Pernicious Kingdoms
2006-07-19 (CWE Draft 3, 2006-07-19)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships, Other_Notes, Taxonomy_Mappings
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Other_Notes
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Demonstrative_Examples
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Other_Notes, References
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Other_Notes, References
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Other_Notes
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Other_Notes, References
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2013-02-21	CWE Content Team	MITRE
2013-02-21	updated Applicable_Platforms, References
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Alternate_Terms, Demonstrative_Examples, Description, Name, Other_Notes, References
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Modes_of_Introduction, References, Relationships
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated Relationships
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Alternate_Terms, Applicable_Platforms, Demonstrative_Examples, Description, Detection_Factors, Maintenance_Notes, Name, Potential_Mitigations, References, Relationships, Type
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Related_Attack_Patterns
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated References
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Related_Attack_Patterns
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2014-02-18	Privacy Violation

2020-02-24	Exposure of Private Information ('Privacy Violation')

Weakness ID: 209

View customized information:

Description

The product generates an error message that includes sensitive information about its environment, users, or associated data.

Extended Description

The sensitive information may be valuable information on its own (such as a password), or it may be useful for launching other, more serious attacks. The error message may be created in different ways:

self-generated: the source code explicitly constructs the error message and delivers it
externally-generated: the external environment, such as a language interpreter, handles the error and constructs its own message, whose contents are not under direct control by the programmer

An attacker may use the contents of error messages to help launch another, more focused attack. For example, an attempt to exploit a path traversal weakness (CWE-22) might yield the full pathname of the installed application. In turn, this could be used to select the proper number of ".." sequences to navigate to the targeted file. An attack using SQL injection (CWE-89) might not initially succeed, but an error message could reveal the malformed query, which would expose query logic and possibly even passwords or other sensitive information used within the query.

Common Consequences

Scope	Impact	Likelihood
Confidentiality	Technical Impact: Read Application Data Often this will either reveal sensitive information which may be used for a later attack or private information stored in the server.

Potential Mitigations

Phase: Implementation

Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.

If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.

Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.

Phase: Implementation

Handle exceptions internally and do not display errors containing potentially sensitive information to a user.

Phase: Implementation

Strategy: Attack Surface Reduction

Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.

Effectiveness: Defense in Depth

Note: This makes it easier to spot places in the code where data is being used that is unencrypted.

Phases: Implementation; Build and Compilation

Strategy: Compilation or Build Hardening

Debugging information should not make its way into a production release.

Phases: Implementation; Build and Compilation

Strategy: Environment Hardening

Debugging information should not make its way into a production release.

Phase: System Configuration

Where available, configure the environment to use less verbose error messages. For example, in PHP, disable the display_errors setting during configuration, or at runtime using the error_reporting() function.

Phase: System Configuration

Create default error pages or messages that do not leak any information.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	755	Improper Handling of Exceptional Conditions
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	200	Exposure of Sensitive Information to an Unauthorized Actor
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	210	Self-generated Error Message Containing Sensitive Information
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	211	Externally-Generated Error Message Containing Sensitive Information
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	550	Server-generated Error Message Containing Sensitive Information
PeerOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1295	Debug Messages Revealing Unnecessary Information
CanFollow	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	600	Uncaught Exception in Servlet
CanFollow	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	756	Missing Custom Error Page

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	199	Information Management Errors
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	389	Error Conditions, Return Values, Status Codes

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	200	Exposure of Sensitive Information to an Unauthorized Actor

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1015	Limit Access

Modes Of Introduction

Phase	Note
Architecture and Design
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic.
System Configuration
Operation

Applicable Platforms

Languages

PHP (Often Prevalent)

Java (Often Prevalent)

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

In the following example, sensitive information might be printed depending on the exception that occurs.

(bad code)

Example Language: Java

try {

/.../

}
catch (Exception e) {

System.out.println(e);

}

If an exception related to SQL is handled by the catch, then the output might contain sensitive information such as SQL query structure or private information. If this output is redirected to a web user, this may represent a security problem.

Example 2

This code tries to open a database connection, and prints any exceptions that occur.

(bad code)

Example Language: PHP

try {

openDbConnection();

}
//print exception message that includes exception message and configuration file location
catch (Exception $e) {

echo 'Caught exception: ', $e->getMessage(), '\n';
echo 'Check credentials in config file at: ', $Mysql_config_location, '\n';

}

If an exception occurs, the printed message exposes the location of the configuration file the script is using. An attacker can use this information to target the configuration file (perhaps exploiting a Path Traversal weakness). If the file can be read, the attacker could gain credentials for accessing the database. The attacker may also be able to replace the file with a malicious one, causing the application to use an arbitrary database.

Example 3

The following code generates an error message that leaks the full pathname of the configuration file.

(bad code)

Example Language: Perl

$ConfigDir = "/home/myprog/config";
$uname = GetUserInput("username");

# avoid CWE-22, CWE-78, others.
ExitError("Bad hacker!") if ($uname !~ /^\w+$/);
$file = "$ConfigDir/$uname.txt";
if (! (-e $file)) {

ExitError("Error: $file does not exist");

}
...

If this code is running on a server, such as a web application, then the person making the request should not know what the full pathname of the configuration directory is. By submitting a username that does not produce a $file that exists, an attacker could get this pathname. It could then be used to exploit path traversal or symbolic link following problems that may exist elsewhere in the application.

Example 4

In the example below, the method getUserBankAccount retrieves a bank account object from a database using the supplied username and account number to query the database. If an SQLException is raised when querying the database, an error message is created and output to a log file.

(bad code)

Example Language: Java

public BankAccount getUserBankAccount(String username, String accountNumber) {

BankAccount userAccount = null;
String query = null;
try {

if (isAuthorizedUser(username)) {

query = "SELECT * FROM accounts WHERE owner = "
+ username + " AND accountID = " + accountNumber;
DatabaseManager dbManager = new DatabaseManager();
Connection conn = dbManager.getConnection();
Statement stmt = conn.createStatement();
ResultSet queryResult = stmt.executeQuery(query);
userAccount = (BankAccount)queryResult.getObject(accountNumber);

}

} catch (SQLException ex) {

String logMessage = "Unable to retrieve account information from database,\nquery: " + query;
Logger.getLogger(BankManager.class.getName()).log(Level.SEVERE, logMessage, ex);

}
return userAccount;

}

The error message that is created includes information about the database query that may contain sensitive information about the database or query logic. In this case, the error message will expose the table name and column names used in the database. This data could be used to simplify other attacks, such as SQL injection (CWE-89) to directly access the database.

Observed Examples

Reference	Description
CVE-2008-2049	POP3 server reveals a password in an error message after multiple APOP commands are sent. Might be resultant from another weakness.
CVE-2007-5172	Program reveals password in error message if attacker can trigger certain database errors.
CVE-2008-4638	Composite: application running with high privileges (CWE-250) allows user to specify a restricted file to process, which generates a parsing error that leaks the contents of the file (CWE-209).
CVE-2008-1579	Existence of user names can be determined by requesting a nonexistent blog and reading the error message.
CVE-2007-1409	Direct request to library file in web application triggers pathname leak in error message.
CVE-2008-3060	Malformed input to login page causes leak of full path when IMAP call fails.
CVE-2005-0603	Malformed regexp syntax leads to information exposure in error message.
CVE-2017-9615	verbose logging stores admin credentials in a world-readablelog file
CVE-2018-1999036	SSH password for private key stored in build log

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)
Resultant	(where the weakness is typically related to the presence of some other weaknesses)

Detection Methods

Manual Analysis

This weakness generally requires domain-specific interpretation using manual analysis. However, the number of potential error conditions may be too large to cover completely within limited time constraints.

Effectiveness: High

Automated Analysis

Automated methods may be able to detect certain idioms automatically, such as exposed stack traces or pathnames, but violation of business rules or privacy requirements is not typically feasible.

Effectiveness: Moderate

Automated Dynamic Analysis

Error conditions may be triggered with a stress-test by calling the software simultaneously from a large number of threads or processes, and look for evidence of any unexpected behavior.

Effectiveness: Moderate

Manual Dynamic Analysis

Identify error conditions that are not likely to occur during normal usage and trigger them. For example, run the program under low memory conditions, run with insufficient privileges or permissions, interrupt a transaction before it is completed, or disable connectivity to basic network services such as DNS. Monitor the software for any unexpected behavior. If you trigger an unhandled exception or similar error that was discovered and handled by the application's environment, it may still indicate unexpected conditions that were not handled by the application itself.

Automated Static Analysis

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	717	OWASP Top Ten 2007 Category A6 - Information Leakage and Improper Error Handling
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	728	OWASP Top Ten 2004 Category A7 - Improper Error Handling
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	731	OWASP Top Ten 2004 Category A10 - Insecure Configuration Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	751	2009 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	801	2010 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	815	OWASP Top Ten 2010 Category A6 - Security Misconfiguration
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	851	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	867	2011 Top 25 - Weaknesses On the Cusp
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	880	CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	933	OWASP Top Ten 2013 Category A5 - Security Misconfiguration
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	963	SFP Secondary Cluster: Exposed Data
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1032	OWASP Top Ten 2017 Category A6 - Security Misconfiguration
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1348	OWASP Top Ten 2021 Category A04:2021 - Insecure Design
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1417	Comprehensive Categorization: Sensitive Information Exposure

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
CLASP			Accidental leaking of sensitive information through error messages
OWASP Top Ten 2007	A6	CWE More Specific	Information Leakage and Improper Error Handling
OWASP Top Ten 2004	A7	CWE More Specific	Improper Error Handling
OWASP Top Ten 2004	A10	CWE More Specific	Insecure Configuration Management
The CERT Oracle Secure Coding Standard for Java (2011)	ERR01-J		Do not allow exceptions to expose sensitive information
Software Fault Patterns	SFP23		Exposed Data

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-215	Fuzzing for application mapping
CAPEC-463	Padding Oracle Crypto Attack
CAPEC-54	Query System for Information
CAPEC-7	Blind SQL Injection

References

[REF-174] Web Application Security Consortium. "Information Leakage". <http://projects.webappsec.org/w/page/13246936/Information%20Leakage>. URL validated: 2023-04-07.

[REF-175] Brian Chess and Jacob West. "Secure Programming with Static Analysis". Section 9.2, Page 326. Addison-Wesley. 2007.

[REF-176] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 16, "General Good Practices." Page 415. 1st Edition. Microsoft Press. 2001-11-13.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 11: Failure to Handle Errors Correctly." Page 183. McGraw-Hill. 2010.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 12: Information Leakage." Page 191. McGraw-Hill. 2010.

[REF-179] Johannes Ullrich. "Top 25 Series - Rank 16 - Information Exposure Through an Error Message". SANS Software Security Institute. 2010-03-17. <http://software-security.sans.org/blog/2010/03/17/top-25-series-rank-16-information-exposure-through-an-error-message>.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 3, "Overly Verbose Error Messages", Page 75. 1st Edition. Addison Wesley. 2006.

[REF-18] Secure Software, Inc.. "The CLASP Application Security Process". 2005. <https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	CLASP
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2022-07-11	Nick Johnston
2022-07-11	Identified incorrect language tag in demonstrative example.
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-08-15		Veracode
2008-08-15	Suggested OWASP Top Ten 2004 mapping
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Applicable_Platforms, Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Relationships
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Demonstrative_Examples, Description, Name, Observed_Examples, Other_Notes, Potential_Mitigations, Relationships, Time_of_Introduction
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Demonstrative_Examples, Potential_Mitigations, Relationships
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Demonstrative_Examples, Name, Potential_Mitigations, References, Time_of_Introduction
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Detection_Factors, References, Relationships
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Related_Attack_Patterns
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, Detection_Factors, Potential_Mitigations, References
2010-09-09		Veracode
2010-09-09	Suggested OWASP Top Ten mapping
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Potential_Mitigations, Relationships
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Demonstrative_Examples, Observed_Examples, Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated References, Related_Attack_Patterns, Relationships
2013-07-17	CWE Content Team	MITRE
2013-07-17	updated References
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, Modes_of_Introduction, References, Relationships, Taxonomy_Mappings
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References, Relationships
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Demonstrative_Examples, Observed_Examples
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Description, Name, Observed_Examples, References, Relationships, Weakness_Ordinalities
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Potential_Mitigations, Related_Attack_Patterns
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Demonstrative_Examples
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2009-01-12	Error Message Information Leaks

2009-12-28	Error Message Information Leak

2020-02-24	Information Exposure Through an Error Message

Weakness ID: 703

Vulnerability Mapping: DISCOURAGEDThis CWE ID should not be used to map to real-world vulnerabilities
Abstraction: PillarPillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.

View customized information:

Description

The product does not properly anticipate or handle exceptional conditions that rarely occur during normal operation of the product.

Common Consequences

Scope	Impact	Likelihood
Confidentiality Availability Integrity	Technical Impact: Read Application Data; DoS: Crash, Exit, or Restart; Unexpected State

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1000	Research Concepts
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	228	Improper Handling of Syntactically Invalid Structure
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	393	Return of Wrong Status Code
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	397	Declaration of Throws for Generic Exception
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	754	Improper Check for Unusual or Exceptional Conditions
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	755	Improper Handling of Exceptional Conditions
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	1384	Improper Handling of Physical or Environmental Conditions

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1012	Cross Cutting

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	248	Uncaught Exception
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	391	Unchecked Error Condition
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	392	Missing Report of Error Condition

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	248	Uncaught Exception
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	391	Unchecked Error Condition
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	392	Missing Report of Error Condition

Modes Of Introduction

Phase	Note
Architecture and Design
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic.
Operation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: Not Technology-Specific (Undetermined Prevalence)

Demonstrative Examples

Example 1

Consider the following code segment:

(bad code)

Example Language: C

char buf[10], cp_buf[10];
fgets(buf, 10, stdin);
strcpy(cp_buf, buf);

The programmer expects that when fgets() returns, buf will contain a null-terminated string of length 9 or less. But if an I/O error occurs, fgets() will not null-terminate buf. Furthermore, if the end of the file is reached before any characters are read, fgets() returns without writing anything to buf. In both of these situations, fgets() signals that something unusual has happened by returning NULL, but in this code, the warning will not be noticed. The lack of a null terminator in buf can result in a buffer overflow in the subsequent call to strcpy().

Example 2

The following method throws three types of exceptions.

(good code)

Example Language: Java

public void doExchange() throws IOException, InvocationTargetException, SQLException {

...

}

While it might seem tidier to write

(bad code)

public void doExchange() throws Exception {

...

}

doing so hampers the caller's ability to understand and handle the exceptions that occur. Further, if a later revision of doExchange() introduces a new type of exception that should be treated differently than previous exceptions, there is no easy way to enforce this requirement.

Observed Examples

Reference	Description
	Chain: JavaScript-based cryptocurrency library can fall back to the insecure Math.random() function instead of reporting a failure (CWE-392), thus reducing the entropy (CWE-332) and leading to generation of non-unique cryptographic keys for Bitcoin wallets (CWE-1391)
CVE-2022-22224	Chain: an operating system does not properly process malformed Open Shortest Path First (OSPF) Type/Length/Value Identifiers (TLV) (CWE-703), which can cause the process to enter an infinite loop (CWE-835)

Detection Methods

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Fault Injection - source code

Fault Injection - binary

Cost effective for partial coverage:

Forced Path Execution

Effectiveness: High

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Manual Source Code Review (not inspections)

Cost effective for partial coverage:

Focused Manual Spotcheck - Focused manual analysis of source

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Source code Weakness Analyzer

Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Formal Methods / Correct-By-Construction

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	851	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 8 - Exceptional Behavior (ERR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	876	CERT C++ Secure Coding Section 08 - Memory Management (MEM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	880	CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	961	SFP Secondary Cluster: Incorrect Exception Behavior
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1141	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 07. Exceptional Behavior (ERR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1306	CISQ Quality Measures - Reliability
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1405	Comprehensive Categorization: Improper Check or Handling of Exceptional Conditions

Vulnerability Mapping Notes

Usage: DISCOURAGED

(this CWE ID should not be used to map to real-world vulnerabilities)

Reason: Abstraction

Rationale:

This CWE entry is extremely high-level, a Pillar.

Comments:

Consider children or descendants of this entry instead.

Notes

Relationship

This is a high-level class that might have some overlap with other classes. It could be argued that even "normal" weaknesses such as buffer overflows involve unusual or exceptional conditions. In that sense, this might be an inherent aspect of most other weaknesses within CWE, similar to API Abuse (CWE-227) and Indicator of Poor Code Quality (CWE-398). However, this entry is currently intended to unify disparate concepts that do not have other places within the Research Concepts view (CWE-1000).

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
The CERT Oracle Secure Coding Standard for Java (2011)	ERR06-J		Do not throw undeclared checked exceptions

References

[REF-567] Taimur Aslam. "A Taxonomy of Security Faults in the UNIX Operating System". 1995-08-01. <http://ftp.cerias.purdue.edu/pub/papers/taimur-aslam/aslam-taxonomy-msthesis.pdf>.

[REF-568] Taimur Aslam, Ivan Krsul and Eugene H. Spafford. "Use of A Taxonomy of Security Faults". 1995-08-01. <https://csrc.nist.gov/csrc/media/publications/conference-paper/1996/10/22/proceedings-of-the-19th-nissc-1996/documents/paper057/paper.pdf>. URL validated: 2023-04-07.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 8: C++ Catastrophes." Page 143. McGraw-Hill. 2010.

[REF-1374] Unciphered. "Randstorm: You Can't Patch a House of Cards". 2023-11-14. <https://www.unciphered.com/blog/randstorm-you-cant-patch-a-house-of-cards>. URL validated: 2023-11-15.

Content History

Submissions
Submission Date	Submitter	Organization
2008-09-09 (CWE 1.0, 2008-09-09)	CWE Content Team	MITRE
2008-09-09 (CWE 1.0, 2008-09-09)	Note: this date reflects when the entry was first published. Draft versions of this entry were provided to members of the CWE community and modified between Draft 9 and 1.0.
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Relationships
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Other_Notes
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Relationships
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Name, Relationship_Notes
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Common_Consequences
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated References, Relationships, Taxonomy_Mappings
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Detection_Factors, Relationships
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, Modes_of_Introduction, References, Relationships, Taxonomy_Mappings
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Relationships, Type
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-04-28	CWE Content Team	MITRE
2022-04-28	updated Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description, Relationships
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
2023-10-26	CWE Content Team	MITRE
2023-10-26	updated Observed_Examples
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Demonstrative_Examples, Observed_Examples, References, Relationships
Previous Entry Names
Change Date	Previous Entry Name
2010-12-13	Failure to Handle Exceptional Conditions

Weakness ID: 116

View customized information:

Description

Extended Description

Improper encoding or escaping can allow attackers to change the commands that are sent to another component, inserting malicious commands instead.

Most products follow a certain protocol that uses structured messages for communication between components, such as queries or commands. These structured messages can contain raw data interspersed with metadata or control information. For example, "GET /index.html HTTP/1.1" is a structured message containing a command ("GET") with a single argument ("/index.html") and metadata about which protocol version is being used ("HTTP/1.1").

If an application uses attacker-supplied inputs to construct a structured message without properly encoding or escaping, then the attacker could insert special characters that will cause the data to be interpreted as control information or metadata. Consequently, the component that receives the output will perform the wrong operations, or otherwise interpret the data incorrectly.

Alternate Terms

Output Sanitization
Output Validation
Output Encoding

Common Consequences

Scope	Impact	Likelihood
Integrity	Technical Impact: Modify Application Data The communications between components can be modified in unexpected ways. Unexpected commands can be executed, bypassing other security mechanisms. Incoming data can be misinterpreted.
Integrity Confidentiality Availability Access Control	Technical Impact: Execute Unauthorized Code or Commands The communications between components can be modified in unexpected ways. Unexpected commands can be executed, bypassing other security mechanisms. Incoming data can be misinterpreted.
Confidentiality	Technical Impact: Bypass Protection Mechanism The communications between components can be modified in unexpected ways. Unexpected commands can be executed, bypassing other security mechanisms. Incoming data can be misinterpreted.

Potential Mitigations

Phase: Architecture and Design

Strategy: Libraries or Frameworks

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.

Alternately, use built-in functions, but consider using wrappers in case those functions are discovered to have a vulnerability.

Phase: Architecture and Design

Strategy: Parameterization

If available, use structured mechanisms that automatically enforce the separation between data and code. These mechanisms may be able to provide the relevant quoting, encoding, and validation automatically, instead of relying on the developer to provide this capability at every point where output is generated.

For example, stored procedures can enforce database query structure and reduce the likelihood of SQL injection.

Phases: Architecture and Design; Implementation

Understand the context in which your data will be used and the encoding that will be expected. This is especially important when transmitting data between different components, or when generating outputs that can contain multiple encodings at the same time, such as web pages or multi-part mail messages. Study all expected communication protocols and data representations to determine the required encoding strategies.

Phase: Architecture and Design

In some cases, input validation may be an important strategy when output encoding is not a complete solution. For example, you may be providing the same output that will be processed by multiple consumers that use different encodings or representations. In other cases, you may be required to allow user-supplied input to contain control information, such as limited HTML tags that support formatting in a wiki or bulletin board. When this type of requirement must be met, use an extremely strict allowlist to limit which control sequences can be used. Verify that the resulting syntactic structure is what you expect. Use your normal encoding methods for the remainder of the input.

Phase: Architecture and Design

Use input validation as a defense-in-depth measure to reduce the likelihood of output encoding errors (see CWE-20).

Phase: Requirements

Fully specify which encodings are required by components that will be communicating with each other.

Phase: Implementation

When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	707	Improper Neutralization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	117	Improper Output Neutralization for Logs
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	644	Improper Neutralization of HTTP Headers for Scripting Syntax
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	838	Inappropriate Encoding for Output Context
CanPrecede	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	74	Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	838	Inappropriate Encoding for Output Context

Modes Of Introduction

Phase	Note
Implementation
Operation

Applicable Platforms

Languages

Class: Not Language-Specific (Often Prevalent)

Technologies

AI/ML (Undetermined Prevalence)

Database Server (Often Prevalent)

Web Server (Often Prevalent)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

This code displays an email address that was submitted as part of a form.

(bad code)

Example Language: JSP

<% String email = request.getParameter("email"); %>
...
Email Address: <%= email %>

The value read from the form parameter is reflected back to the client browser without having been encoded prior to output, allowing various XSS attacks (CWE-79).

Example 2

Consider a chat application in which a front-end web application communicates with a back-end server. The back-end is legacy code that does not perform authentication or authorization, so the front-end must implement it. The chat protocol supports two commands, SAY and BAN, although only administrators can use the BAN command. Each argument must be separated by a single space. The raw inputs are URL-encoded. The messaging protocol allows multiple commands to be specified on the same line if they are separated by a "|" character.

First let's look at the back end command processor code

(bad code)

Example Language: Perl

$inputString = readLineFromFileHandle($serverFH);

# generate an array of strings separated by the "|" character.
@commands = split(/\|/, $inputString);

foreach $cmd (@commands) {

# separate the operator from its arguments based on a single whitespace
($operator, $args) = split(/ /, $cmd, 2);

$args = UrlDecode($args);
if ($operator eq "BAN") {

ExecuteBan($args);

}
elsif ($operator eq "SAY") {

ExecuteSay($args);

}

The front end web application receives a command, encodes it for sending to the server, performs the authorization check, and sends the command to the server.

(bad code)

Example Language: Perl

$inputString = GetUntrustedArgument("command");
($cmd, $argstr) = split(/\s+/, $inputString, 2);

# removes extra whitespace and also changes CRLF's to spaces
$argstr =~ s/\s+/ /gs;

$argstr = UrlEncode($argstr);
if (($cmd eq "BAN") && (! IsAdministrator($username))) {

die "Error: you are not the admin.\n";

}

# communicate with file server using a file handle
$fh = GetServerFileHandle("myserver");

print $fh "$cmd $argstr\n";

It is clear that, while the protocol and back-end allow multiple commands to be sent in a single request, the front end only intends to send a single command. However, the UrlEncode function could leave the "|" character intact. If an attacker provides:

(attack code)

SAY hello world|BAN user12

then the front end will see this is a "SAY" command, and the $argstr will look like "hello world | BAN user12". Since the command is "SAY", the check for the "BAN" command will fail, and the front end will send the URL-encoded command to the back end:

(result)

SAY hello%20world|BAN%20user12

The back end, however, will treat these as two separate commands:

(result)

SAY hello world
BAN user12

Notice, however, that if the front end properly encodes the "|" with "%7C", then the back end will only process a single command.

Example 3

This example takes user input, passes it through an encoding scheme and then creates a directory specified by the user.

(bad code)

Example Language: Perl

sub GetUntrustedInput {

return($ARGV[0]);

}

sub encode {

my($str) = @_;
$str =~ s/\&/\&/gs;
$str =~ s/\"/\"/gs;
$str =~ s/\'/\'/gs;
$str =~ s/\</\</gs;
$str =~ s/\>/\>/gs;
return($str);

}

sub doit {

my $uname = encode(GetUntrustedInput("username"));
print "<b>Welcome, $uname!</b><p>\n";
system("cd /home/$uname; /bin/ls -l");

}

The programmer attempts to encode dangerous characters, however the denylist for encoding is incomplete (CWE-184) and an attacker can still pass a semicolon, resulting in a chain with command injection (CWE-77).

Additionally, the encoding routine is used inappropriately with command execution. An attacker doesn't even need to insert their own semicolon. The attacker can instead leverage the encoding routine to provide the semicolon to separate the commands. If an attacker supplies a string of the form:

(attack code)

' pwd

then the program will encode the apostrophe and insert the semicolon, which functions as a command separator when passed to the system function. This allows the attacker to complete the command injection.

Observed Examples

Reference	Description
CVE-2021-41232	Chain: authentication routine in Go-based agile development product does not escape user name (CWE-116), allowing LDAP injection (CWE-90)
CVE-2008-4636	OS command injection in backup software using shell metacharacters in a filename; correct behavior would require that this filename could not be changed.
CVE-2008-0769	Web application does not set the charset when sending a page to a browser, allowing for XSS exploitation when a browser chooses an unexpected encoding.
CVE-2008-0005	Program does not set the charset when sending a page to a browser, allowing for XSS exploitation when a browser chooses an unexpected encoding.
CVE-2008-5573	SQL injection via password parameter; a strong password might contain "&"
CVE-2008-3773	Cross-site scripting in chat application via a message subject, which normally might contain "&" and other XSS-related characters.
CVE-2008-0757	Cross-site scripting in chat application via a message, which normally might be allowed to contain arbitrary content.

Detection Methods

Automated Static Analysis

This weakness can often be detected using automated static analysis tools. Many modern tools use data flow analysis or constraint-based techniques to minimize the number of false positives.

Effectiveness: Moderate

Note: This is not a perfect solution, since 100% accuracy and coverage are not feasible.

Automated Dynamic Analysis

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	751	2009 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	845	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 2 - Input Validation and Data Sanitization (IDS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	883	CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	992	SFP Secondary Cluster: Faulty Input Transformation
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1134	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 00. Input Validation and Data Sanitization (IDS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1179	SEI CERT Perl Coding Standard - Guidelines 01. Input Validation and Data Sanitization (IDS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1347	OWASP Top Ten 2021 Category A03:2021 - Injection
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1407	Comprehensive Categorization: Improper Neutralization

Vulnerability Mapping Notes

Usage: ALLOWED-WITH-REVIEW

(this CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review)

Reason: Abstraction

Rationale:

This CWE entry is a Class and might have Base-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit

Notes

Relationship

This weakness is primary to all weaknesses related to injection (CWE-74) since the inherent nature of injection involves the violation of structured messages.

Relationship

CWE-116 and CWE-20 have a close association because, depending on the nature of the structured message, proper input validation can indirectly prevent special characters from changing the meaning of a structured message. For example, by validating that a numeric ID field should only contain the 0-9 characters, the programmer effectively prevents injection attacks.

However, input validation is not always sufficient, especially when less stringent data types must be supported, such as free-form text. Consider a SQL injection scenario in which a last name is inserted into a query. The name "O'Reilly" would likely pass the validation step since it is a common last name in the English language. However, it cannot be directly inserted into the database because it contains the "'" apostrophe character, which would need to be escaped or otherwise neutralized. In this case, stripping the apostrophe might reduce the risk of SQL injection, but it would produce incorrect behavior because the wrong name would be recorded.

Terminology

The usage of the "encoding" and "escaping" terms varies widely. For example, in some programming languages, the terms are used interchangeably, while other languages provide APIs that use both terms for different tasks. This overlapping usage extends to the Web, such as the "escape" JavaScript function whose purpose is stated to be encoding. The concepts of encoding and escaping predate the Web by decades. Given such a context, it is difficult for CWE to adopt a consistent vocabulary that will not be misinterpreted by some constituency.

Theoretical

This is a data/directive boundary error in which data boundaries are not sufficiently enforced before it is sent to a different control sphere.

Research Gap

While many published vulnerabilities are related to insufficient output encoding, there is such an emphasis on input validation as a protection mechanism that the underlying causes are rarely described. Within CVE, the focus is primarily on well-understood issues like cross-site scripting and SQL injection. It is likely that this weakness frequently occurs in custom protocols that support multiple encodings, which are not necessarily detectable with automated techniques.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
WASC	22		Improper Output Handling
The CERT Oracle Secure Coding Standard for Java (2011)	IDS00-J	Exact	Sanitize untrusted data passed across a trust boundary
The CERT Oracle Secure Coding Standard for Java (2011)	IDS05-J		Use a subset of ASCII for file and path names
SEI CERT Oracle Coding Standard for Java	IDS00-J	Imprecise	Prevent SQL injection
SEI CERT Perl Coding Standard	IDS33-PL	Exact	Sanitize untrusted data passed across a trust boundary

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-104	Cross Zone Scripting
CAPEC-73	User-Controlled Filename
CAPEC-81	Web Server Logs Tampering
CAPEC-85	AJAX Footprinting

References

[REF-45] OWASP. "OWASP Enterprise Security API (ESAPI) Project". <http://www.owasp.org/index.php/ESAPI>.

[REF-46] Joshbw. "Output Sanitization". 2008-09-18. <https://web.archive.org/web/20081208054333/http://analyticalengine.net/archives/58>. URL validated: 2023-04-07.

[REF-47] Niyaz PK. "Sanitizing user data: How and where to do it". 2008-09-11. <https://web.archive.org/web/20090105222005/http://www.diovo.com/2008/09/sanitizing-user-data-how-and-where-to-do-it/>. URL validated: 2023-04-07.

[REF-48] Jeremiah Grossman. "Input validation or output filtering, which is better?". 2007-01-30. <https://blog.jeremiahgrossman.com/2007/01/input-validation-or-output-filtering.html>. URL validated: 2023-04-07.

[REF-49] Jim Manico. "Input Validation - Not That Important". 2008-08-10. <https://manicode.blogspot.com/2008/08/input-validation-not-that-important.html>. URL validated: 2023-04-07.

[REF-50] Michael Eddington. "Preventing XSS with Correct Output Encoding". <http://phed.org/2008/05/19/preventing-xss-with-correct-output-encoding/>.

[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 11, "Canonical Representation Issues" Page 363. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	CWE Community
2006-07-19 (CWE Draft 3, 2006-07-19)	Submitted by members of the CWE community to extend early CWE versions
Modifications
Modification Date	Modifier	Organization
2008-07-01	Sean Eidemiller	Cigital
2008-07-01	added/updated demonstrative examples
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Name, Relationships
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Alternate_Terms, Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Description, Likelihood_of_Exploit, Name, Observed_Examples, Potential_Mitigations, References, Relationship_Notes, Relationships, Research_Gaps, Terminology_Notes, Theoretical_Notes
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Description, Potential_Mitigations
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Related_Attack_Patterns
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Demonstrative_Examples
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Relationships
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Demonstrative_Examples, Potential_Mitigations
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Detection_Factors, Potential_Mitigations, References, Taxonomy_Mappings
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Potential_Mitigations
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Potential_Mitigations
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Relationship_Notes, Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated References, Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated References
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Demonstrative_Examples, Relationships
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Relationships
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Relationships
2017-05-03	CWE Content Team	MITRE
2017-05-03	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Likelihood_of_Exploit, References, Taxonomy_Mappings
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Relationships
2020-06-25	CWE Content Team	MITRE
2020-06-25	updated Applicable_Platforms, Demonstrative_Examples, Potential_Mitigations
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Relationships, Terminology_Notes
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Observed_Examples
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships, Time_of_Introduction
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2024-07-16 (CWE 4.15, 2024-07-16)	CWE Content Team	MITRE
2024-07-16 (CWE 4.15, 2024-07-16)	updated Applicable_Platforms
Previous Entry Names
Change Date	Previous Entry Name
2008-04-11	Output Validation

2008-09-09	Incorrect Output Sanitization

2009-01-12	Insufficient Output Sanitization

Weakness ID: 665

Vulnerability Mapping: DISCOURAGEDThis CWE ID should not be used to map to real-world vulnerabilities
Abstraction: ClassClass - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.

View customized information:

Description

The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used.

Extended Description

This can have security implications when the associated resource is expected to have certain properties or values, such as a variable that determines whether a user has been authenticated or not.

Common Consequences

Scope	Impact	Likelihood
Confidentiality	Technical Impact: Read Memory; Read Application Data When reusing a resource such as memory or a program variable, the original contents of that resource may not be cleared before it is sent to an untrusted party.
Access Control	Technical Impact: Bypass Protection Mechanism If security-critical decisions rely on a variable having a "0" or equivalent value, and the programming language performs this initialization on behalf of the programmer, then a bypass of security may occur.
Availability	Technical Impact: DoS: Crash, Exit, or Restart The uninitialized data may contain values that cause program flow to change in ways that the programmer did not intend. For example, if an uninitialized variable is used as an array index in C, then its previous contents may produce an index that is outside the range of the array, possibly causing a crash or an exit in other environments.

Potential Mitigations

Phase: Requirements

Strategy: Language Selection

Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

For example, in Java, if the programmer does not explicitly initialize a variable, then the code could produce a compile-time error (if the variable is local) or automatically initialize the variable to the default value for the variable's type. In Perl, if explicit initialization is not performed, then a default value of undef is assigned, which is interpreted as 0, false, or an equivalent value depending on the context in which the variable is accessed.

Phase: Architecture and Design

Identify all variables and data stores that receive information from external sources, and apply input validation to make sure that they are only initialized to expected values.

Phase: Implementation

Explicitly initialize all your variables and other data stores, either during declaration or just before the first usage.

Phase: Implementation

Pay close attention to complex conditionals that affect initialization, since some conditions might not perform the initialization.

Phase: Implementation

Avoid race conditions (CWE-362) during initialization routines.

Phase: Build and Compilation

Run or compile your product with settings that generate warnings about uninitialized variables or data.

Phase: Testing

Use automated static analysis tools that target this type of weakness. Many modern techniques use data flow analysis to minimize the number of false positives. This is not a perfect solution, since 100% accuracy and coverage are not feasible.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	664	Improper Control of a Resource Through its Lifetime
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	455	Non-exit on Failed Initialization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	770	Allocation of Resources Without Limits or Throttling
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	908	Use of Uninitialized Resource
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	909	Missing Initialization of Resource
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1279	Cryptographic Operations are run Before Supporting Units are Ready
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	1419	Incorrect Initialization of Resource

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	908	Use of Uninitialized Resource
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	909	Missing Initialization of Resource
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1188	Initialization of a Resource with an Insecure Default

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	456	Missing Initialization of a Variable
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	457	Use of Uninitialized Variable

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	456	Missing Initialization of a Variable
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	457	Use of Uninitialized Variable

Modes Of Introduction

Phase	Note
Implementation	This weakness can occur in code paths that are not well-tested, such as rare error conditions. This is because the use of uninitialized data would be noticed as a bug during frequently-used functionality.
Operation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

Here, a boolean initiailized field is consulted to ensure that initialization tasks are only completed once. However, the field is mistakenly set to true during static initialization, so the initialization code is never reached.

(bad code)

Example Language: Java

private boolean initialized = true;
public void someMethod() {

if (!initialized) {

// perform initialization tasks
...

initialized = true;

}

Example 2

The following code intends to limit certain operations to the administrator only.

(bad code)

Example Language: Perl

$username = GetCurrentUser();
$state = GetStateData($username);
if (defined($state)) {

$uid = ExtractUserID($state);

}

# do stuff
if ($uid == 0) {

DoAdminThings();

}

If the application is unable to extract the state information - say, due to a database timeout - then the $uid variable will not be explicitly set by the programmer. This will cause $uid to be regarded as equivalent to "0" in the conditional, allowing the original user to perform administrator actions. Even if the attacker cannot directly influence the state data, unexpected errors could cause incorrect privileges to be assigned to a user just by accident.

Example 3

The following code intends to concatenate a string to a variable and print the string.

(bad code)

Example Language: C

char str[20];
strcat(str, "hello world");
printf("%s", str);

This might seem innocent enough, but str was not initialized, so it contains random memory. As a result, str[0] might not contain the null terminator, so the copy might start at an offset other than 0. The consequences can vary, depending on the underlying memory.

If a null terminator is found before str[8], then some bytes of random garbage will be printed before the "hello world" string. The memory might contain sensitive information from previous uses, such as a password (which might occur as a result of CWE-14 or CWE-244). In this example, it might not be a big deal, but consider what could happen if large amounts of memory are printed out before the null terminator is found.

If a null terminator isn't found before str[8], then a buffer overflow could occur, since strcat will first look for the null terminator, then copy 12 bytes starting with that location. Alternately, a buffer over-read might occur (CWE-126) if a null terminator isn't found before the end of the memory segment is reached, leading to a segmentation fault and crash.

Observed Examples

Reference	Description
CVE-2001-1471	chain: an invalid value prevents a library file from being included, skipping initialization of key variables, leading to resultant eval injection.
CVE-2008-3637	Improper error checking in protection mechanism produces an uninitialized variable, allowing security bypass and code execution.
CVE-2008-4197	Use of uninitialized memory may allow code execution.
CVE-2008-2934	Free of an uninitialized pointer leads to crash and possible code execution.
CVE-2007-3749	OS kernel does not reset a port when starting a setuid program, allowing local users to access the port and gain privileges.
CVE-2008-0063	Product does not clear memory contents when generating an error message, leading to information leak.
CVE-2008-0062	Lack of initialization triggers NULL pointer dereference or double-free.
CVE-2008-0081	Uninitialized variable leads to code execution in popular desktop application.
CVE-2008-3688	chain: Uninitialized variable leads to infinite loop.
CVE-2008-3475	chain: Improper initialization leads to memory corruption.
CVE-2008-5021	Composite: race condition allows attacker to modify an object while it is still being initialized, causing software to access uninitialized memory.
CVE-2005-1036	Chain: Bypass of access restrictions due to improper authorization (CWE-862) of a user results from an improperly initialized (CWE-909) I/O permission bitmap
CVE-2008-3597	chain: game server can access player data structures before initialization has happened leading to NULL dereference
CVE-2009-2692	chain: uninitialized function pointers can be dereferenced allowing code execution
CVE-2009-0949	chain: improper initialization of memory can lead to NULL dereference
CVE-2009-3620	chain: some unprivileged ioctls do not verify that a structure has been initialized before invocation, leading to NULL dereference

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)
Resultant	(where the weakness is typically related to the presence of some other weaknesses)

Detection Methods

Automated Dynamic Analysis

Initialization problems may be detected with a stress-test by calling the software simultaneously from a large number of threads or processes, and look for evidence of any unexpected behavior. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

Effectiveness: Moderate

Manual Dynamic Analysis

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	740	CERT C Secure Coding Standard (2008) Chapter 7 - Arrays (ARR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	742	CERT C Secure Coding Standard (2008) Chapter 9 - Memory Management (MEM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	752	2009 Top 25 - Risky Resource Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	846	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 3 - Declarations and Initialization (DCL)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	874	CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	876	CERT C++ Secure Coding Section 08 - Memory Management (MEM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	962	SFP Secondary Cluster: Unchecked Status Condition
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1135	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 01. Declarations and Initialization (DCL)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1306	CISQ Quality Measures - Reliability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1416	Comprehensive Categorization: Resource Lifecycle Management

Vulnerability Mapping Notes

Usage: DISCOURAGED

(this CWE ID should not be used to map to real-world vulnerabilities)

Reason: Abstraction

Rationale:

This CWE entry is a level-1 Class (i.e., a child of a Pillar). It might have lower-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
PLOVER		Incorrect initialization
CERT C Secure Coding	ARR02-C	Explicitly specify array bounds, even if implicitly defined by an initializer
The CERT Oracle Secure Coding Standard for Java (2011)	DCL00-J	Prevent class initialization cycles
Software Fault Patterns	SFP4	Unchecked Status Condition

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-26	Leveraging Race Conditions
CAPEC-29	Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions

References

[REF-436] mercy. "Exploiting Uninitialized Data". 2006-01. <http://www.felinemenace.org/~mercy/papers/UBehavior/UBehavior.zip>.

[REF-437] Microsoft Security Vulnerability Research & Defense. "MS08-014 : The Case of the Uninitialized Stack Variable Vulnerability". 2008-03-11. <https://msrc.microsoft.com/blog/2008/03/ms08-014-the-case-of-the-uninitialized-stack-variable-vulnerability/>. URL validated: 2023-04-07.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 7, "Variable Initialization", Page 312. 1st Edition. Addison Wesley. 2006.

Content History

Submissions
Submission Date	Submitter	Organization
2008-04-11 (CWE Draft 9, 2008-04-11)	PLOVER
2008-04-11 (CWE Draft 9, 2008-04-11)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Sean Eidemiller	Cigital
2008-07-01	added/updated demonstrative examples
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Potential_Mitigations, Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships, Taxonomy_Mappings
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Relationships, Taxonomy_Mappings
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Common_Consequences, Demonstrative_Examples, Description, Likelihood_of_Exploit, Modes_of_Introduction, Name, Observed_Examples, Potential_Mitigations, References, Relationships, Weakness_Ordinalities
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Description, Relationships
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Related_Attack_Patterns
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Common_Consequences
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Potential_Mitigations
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Applicable_Platforms
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Detection_Factors, Potential_Mitigations
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Observed_Examples
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, References, Relationships, Taxonomy_Mappings
2013-02-21	CWE Content Team	MITRE
2013-02-21	updated Demonstrative_Examples, Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Relationships
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Type
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated References, Taxonomy_Mappings
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Relationships
2020-06-25	CWE Content Team	MITRE
2020-06-25	updated Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Observed_Examples
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description, Potential_Mitigations, Relationships
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2023-10-26	CWE Content Team	MITRE
2023-10-26	updated Relationships
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2009-01-12	Incorrect or Incomplete Initialization

Weakness ID: 667

View customized information:

Description

The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Extended Description

Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.

Common Consequences

Scope	Impact	Likelihood
Availability	Technical Impact: DoS: Resource Consumption (CPU) Inconsistent locking discipline can lead to deadlock.

Potential Mitigations

Phase: Implementation

Strategy: Libraries or Frameworks

Use industry standard APIs to implement locking mechanism.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	662	Improper Synchronization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	412	Unrestricted Externally Accessible Lock
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	413	Improper Resource Locking
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	414	Missing Lock Check
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	609	Double-Checked Locking
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	764	Multiple Locks of a Critical Resource
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	765	Multiple Unlocks of a Critical Resource
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	832	Unlock of a Resource that is not Locked
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	833	Deadlock
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1232	Improper Lock Behavior After Power State Transition
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1233	Security-Sensitive Hardware Controls with Missing Lock Bit Protection
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1234	Hardware Internal or Debug Modes Allow Override of Locks

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	662	Improper Synchronization

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	662	Improper Synchronization

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	662	Improper Synchronization

Modes Of Introduction

Phase	Note
Architecture and Design
Implementation

Demonstrative Examples

Example 1

In the following Java snippet, methods are defined to get and set a long field in an instance of a class that is shared across multiple threads. Because operations on double and long are nonatomic in Java, concurrent access may cause unexpected behavior. Thus, all operations on long and double fields should be synchronized.

(bad code)

Example Language: Java

private long someLongValue;
public long getLongValue() {

return someLongValue;

}

public void setLongValue(long l) {

someLongValue = l;

}

Example 2

This code tries to obtain a lock for a file, then writes to it.

(bad code)

Example Language: PHP

function writeToLog($message){

$logfile = fopen("logFile.log", "a");
//attempt to get logfile lock
if (flock($logfile, LOCK_EX)) {

fwrite($logfile,$message);
// unlock logfile
flock($logfile, LOCK_UN);

}
else {

print "Could not obtain lock on logFile.log, message not recorded\n";

}

}
fclose($logFile);

PHP by default will wait indefinitely until a file lock is released. If an attacker is able to obtain the file lock, this code will pause execution, possibly leading to denial of service for other users. Note that in this case, if an attacker can perform an flock() on the file, they may already have privileges to destroy the log file. However, this still impacts the execution of other programs that depend on flock().

Example 3

The following function attempts to acquire a lock in order to perform operations on a shared resource.

(bad code)

Example Language: C

void f(pthread_mutex_t *mutex) {

pthread_mutex_lock(mutex);

/* access shared resource */

pthread_mutex_unlock(mutex);

}

(good code)

Example Language: C

int f(pthread_mutex_t *mutex) {

int result;

result = pthread_mutex_lock(mutex);
if (0 != result)

return result;

/* access shared resource */

return pthread_mutex_unlock(mutex);

}

Example 4

It may seem that the following bit of code achieves thread safety while avoiding unnecessary synchronization...

(bad code)

Example Language: Java

if (helper == null) {

synchronized (this) {

if (helper == null) {

helper = new Helper();

}

}
return helper;

The programmer wants to guarantee that only one Helper() object is ever allocated, but does not want to pay the cost of synchronization every time this code is called.

Suppose that helper is not initialized. Then, thread A sees that helper==null and enters the synchronized block and begins to execute:

(bad code)

helper = new Helper();

If a second thread, thread B, takes over in the middle of this call and helper has not finished running the constructor, then thread B may make calls on helper while its fields hold incorrect values.

Observed Examples

Reference	Description
CVE-2021-1782	Chain: improper locking (CWE-667) leads to race condition (CWE-362), as exploited in the wild per CISA KEV.
CVE-2009-0935	Attacker provides invalid address to a memory-reading function, causing a mutex to be unlocked twice
CVE-2010-4210	function in OS kernel unlocks a mutex that was not previously locked, causing a panic or overwrite of arbitrary memory.
CVE-2008-4302	Chain: OS kernel does not properly handle a failure of a function call (CWE-755), leading to an unlock of a resource that was not locked (CWE-832), with resultant crash.
CVE-2009-1243	OS kernel performs an unlock in some incorrect circumstances, leading to panic.
CVE-2009-2857	OS deadlock
CVE-2009-1961	OS deadlock involving 3 separate functions
CVE-2009-2699	deadlock in library
CVE-2009-4272	deadlock triggered by packets that force collisions in a routing table
CVE-2002-1850	read/write deadlock between web server and script
CVE-2004-0174	web server deadlock involving multiple listening connections
CVE-2009-1388	multiple simultaneous calls to the same function trigger deadlock.
CVE-2006-5158	chain: other weakness leads to NULL pointer dereference (CWE-476) or deadlock (CWE-833).
CVE-2006-4342	deadlock when an operation is performed on a resource while it is being removed.
CVE-2006-2374	Deadlock in device driver triggered by using file handle of a related device.
CVE-2006-2275	Deadlock when large number of small messages cannot be processed quickly enough.
CVE-2005-3847	OS kernel has deadlock triggered by a signal during a core dump.
CVE-2005-3106	Race condition leads to deadlock.
CVE-2005-2456	Chain: array index error (CWE-129) leads to deadlock (CWE-833)
CVE-2001-0682	Program can not execute when attacker obtains a mutex.
CVE-2002-1914	Program can not execute when attacker obtains a lock on a critical output file.
CVE-2002-1915	Program can not execute when attacker obtains a lock on a critical output file.
CVE-2002-0051	Critical file can be opened with exclusive read access by user, preventing application of security policy. Possibly related to improper permissions, large-window race condition.
CVE-2000-0338	Chain: predictable file names used for locking, allowing attacker to create the lock beforehand. Resultant from permissions and randomness.
CVE-2000-1198	Chain: Lock files with predictable names. Resultant from randomness.
CVE-2002-1869	Product does not check if it can write to a log file, allowing attackers to avoid logging by accessing the file using an exclusive lock. Overlaps unchecked error condition. This is not quite CWE-412, but close.

Detection Methods

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	748	CERT C Secure Coding Standard (2008) Appendix - POSIX (POS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	852	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 9 - Visibility and Atomicity (VNA)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	853	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 10 - Locking (LCK)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	986	SFP Secondary Cluster: Missing Lock
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1131	CISQ Quality Measures (2016) - Security
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1142	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 08. Visibility and Atomicity (VNA)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1143	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 09. Locking (LCK)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1169	SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1171	SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1401	Comprehensive Categorization: Concurrency

Vulnerability Mapping Notes

Usage: ALLOWED-WITH-REVIEW

(this CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review)

Reason: Abstraction

Rationale:

This CWE entry is a Class and might have Base-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit

Notes

Maintenance

Deeper research is necessary for synchronization and related mechanisms, including locks, mutexes, semaphores, and other mechanisms. Multiple entries are dependent on this research, which includes relationships to concurrency, race conditions, reentrant functions, etc. CWE-662 and its children - including CWE-667, CWE-820, CWE-821, and others - may need to be modified significantly, along with their relationships.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
CERT C Secure Coding	CON31-C	CWE More Abstract	Do not destroy a mutex while it is locked
CERT C Secure Coding	POS48-C	CWE More Abstract	Do not unlock or destroy another POSIX thread's mutex
The CERT Oracle Secure Coding Standard for Java (2011)	VNA00-J		Ensure visibility when accessing shared primitive variables
The CERT Oracle Secure Coding Standard for Java (2011)	VNA02-J		Ensure that compound operations on shared variables are atomic
The CERT Oracle Secure Coding Standard for Java (2011)	VNA05-J		Ensure atomicity when reading and writing 64-bit values
The CERT Oracle Secure Coding Standard for Java (2011)	LCK06-J		Do not use an instance lock to protect shared static data
Software Fault Patterns	SFP19		Missing Lock
OMG ASCSM	ASCSM-CWE-667

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-25	Forced Deadlock
CAPEC-26	Leveraging Race Conditions
CAPEC-27	Leveraging Race Conditions via Symbolic Links

References

[REF-962] Object Management Group (OMG). "Automated Source Code Security Measure (ASCSM)". ASCSM-CWE-667. 2016-01. <http://www.omg.org/spec/ASCSM/1.0/>.

Content History

Submissions
Submission Date	Submitter	Organization
2008-04-11 (CWE Draft 9, 2008-04-11)	CWE Content Team	MITRE
2008-04-11 (CWE Draft 9, 2008-04-11)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Sean Eidemiller	Cigital
2008-07-01	added/updated demonstrative examples
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Potential_Mitigations, Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Relationships, Taxonomy_Mappings
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Related_Attack_Patterns
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Relationships
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Common_Consequences
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Relationships
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Description, Name, Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, Observed_Examples, Relationships
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2017-05-03	CWE Content Team	MITRE
2017-05-03	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Taxonomy_Mappings
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated References, Relationships, Taxonomy_Mappings
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Relationships
2019-09-23	CWE Content Team	MITRE
2019-09-23	updated Description, Maintenance_Notes, Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Relationships, Type
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Demonstrative_Examples
2022-06-28	CWE Content Team	MITRE
2022-06-28	updated Observed_Examples
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2010-12-13	Insufficient Locking

Weakness ID: 78

View customized information:

Description

Extended Description

This weakness can lead to a vulnerability in environments in which the attacker does not have direct access to the operating system, such as in web applications. Alternately, if the weakness occurs in a privileged program, it could allow the attacker to specify commands that normally would not be accessible, or to call alternate commands with privileges that the attacker does not have. The problem is exacerbated if the compromised process does not follow the principle of least privilege, because the attacker-controlled commands may run with special system privileges that increases the amount of damage.

There are at least two subtypes of OS command injection:

The application intends to execute a single, fixed program that is under its own control. It intends to use externally-supplied inputs as arguments to that program. For example, the program might use system("nslookup [HOSTNAME]") to run nslookup and allow the user to supply a HOSTNAME, which is used as an argument. Attackers cannot prevent nslookup from executing. However, if the program does not remove command separators from the HOSTNAME argument, attackers could place the separators into the arguments, which allows them to execute their own program after nslookup has finished executing.
The application accepts an input that it uses to fully select which program to run, as well as which commands to use. The application simply redirects this entire command to the operating system. For example, the program might use "exec([COMMAND])" to execute the [COMMAND] that was supplied by the user. If the COMMAND is under attacker control, then the attacker can execute arbitrary commands or programs. If the command is being executed using functions like exec() and CreateProcess(), the attacker might not be able to combine multiple commands together in the same line.

From a weakness standpoint, these variants represent distinct programmer errors. In the first variant, the programmer clearly intends that input from untrusted parties will be part of the arguments in the command to be executed. In the second variant, the programmer does not intend for the command to be accessible to any untrusted party, but the programmer probably has not accounted for alternate ways in which malicious attackers can provide input.

Alternate Terms

Shell injection
Shell metacharacters
OS Command Injection

Common Consequences

Scope	Impact	Likelihood
Confidentiality Integrity Availability Non-Repudiation	Technical Impact: Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart; Read Files or Directories; Modify Files or Directories; Read Application Data; Modify Application Data; Hide Activities Attackers could execute unauthorized operating system commands, which could then be used to disable the product, or read and modify data for which the attacker does not have permissions to access directly. Since the targeted application is directly executing the commands instead of the attacker, any malicious activities may appear to come from the application or the application's owner.

Potential Mitigations

Phase: Architecture and Design

If at all possible, use library calls rather than external processes to recreate the desired functionality.

Phases: Architecture and Design; Operation

Strategy: Sandbox or Jail

This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.

Be careful to avoid CWE-243 and other weaknesses related to jails.

Effectiveness: Limited

Phase: Architecture and Design

Strategy: Attack Surface Reduction

For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.

Phase: Architecture and Design

Strategy: Libraries or Frameworks

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

For example, consider using the ESAPI Encoding control [REF-45] or a similar tool, library, or framework. These will help the programmer encode outputs in a manner less prone to error.

Phase: Implementation

Strategy: Output Encoding

While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).

Phase: Implementation

If the program to be executed allows arguments to be specified within an input file or from standard input, then consider using that mode to pass arguments instead of the command line.

Phase: Architecture and Design

Strategy: Parameterization

Some languages offer multiple functions that can be used to invoke commands. Where possible, identify any function that invokes a command shell using a single string, and replace it with a function that requires individual arguments. These functions typically perform appropriate quoting and filtering of arguments. For example, in C, the system() function accepts a string that contains the entire command to be executed, whereas execl(), execve(), and others require an array of strings, one for each argument. In Windows, CreateProcess() only accepts one command at a time. In Perl, if system() is provided with an array of arguments, then it will quote each of the arguments.

Phase: Implementation

Strategy: Input Validation

When constructing OS command strings, use stringent allowlists that limit the character set based on the expected value of the parameter in the request. This will indirectly limit the scope of an attack, but this technique is less important than proper output encoding and escaping.

Note that proper output encoding, escaping, and quoting is the most effective solution for preventing OS command injection, although input validation may provide some defense-in-depth. This is because it effectively limits what will appear in output. Input validation will not always prevent OS command injection, especially if you are required to support free-form text fields that could contain arbitrary characters. For example, when invoking a mail program, you might need to allow the subject field to contain otherwise-dangerous inputs like ";" and ">" characters, which would need to be escaped or otherwise handled. In this case, stripping the character might reduce the risk of OS command injection, but it would produce incorrect behavior because the subject field would not be recorded as the user intended. This might seem to be a minor inconvenience, but it could be more important when the program relies on well-structured subject lines in order to pass messages to other components.

Even if you make a mistake in your validation (such as forgetting one out of 100 input fields), appropriate encoding is still likely to protect you from injection-based attacks. As long as it is not done in isolation, input validation is still a useful technique, since it may significantly reduce your attack surface, allow you to detect some attacks, and provide other security benefits that proper encoding does not address.

Phase: Architecture and Design

Strategy: Enforcement by Conversion

When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.

Phase: Operation

Strategy: Compilation or Build Hardening

Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).

Phase: Operation

Strategy: Environment Hardening

Phase: Implementation

Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.

In the context of OS Command Injection, error information passed back to the user might reveal whether an OS command is being executed and possibly which command is being used.

Phase: Operation

Strategy: Sandbox or Jail

Use runtime policy enforcement to create an allowlist of allowable commands, then prevent use of any command that does not appear in the allowlist. Technologies such as AppArmor are available to do this.

Phase: Operation

Strategy: Firewall

Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.

Effectiveness: Moderate

Note: An application firewall might not cover all possible input vectors. In addition, attack techniques might be available to bypass the protection mechanism, such as using malformed inputs that can still be processed by the component that receives those inputs. Depending on functionality, an application firewall might inadvertently reject or modify legitimate requests. Finally, some manual effort may be required for customization.

Phases: Architecture and Design; Operation

Strategy: Environment Hardening

Phases: Operation; Implementation

Strategy: Environment Hardening

When using PHP, configure the application so that it does not use register_globals. During implementation, develop the application so that it does not rely on this feature, but be wary of implementing a register_globals emulation that is subject to weaknesses such as CWE-95, CWE-621, and similar issues.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	77	Improper Neutralization of Special Elements used in a Command ('Command Injection')
CanAlsoBe	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	88	Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
CanFollow	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	184	Incomplete List of Disallowed Inputs

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	137	Data Neutralization Issues

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	74	Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1019	Validate Inputs

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	77	Improper Neutralization of Special Elements used in a Command ('Command Injection')

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	77	Improper Neutralization of Special Elements used in a Command ('Command Injection')

Modes Of Introduction

Phase	Note
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic.

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

This example code intends to take the name of a user and list the contents of that user's home directory. It is subject to the first variant of OS command injection.

(bad code)

Example Language: PHP

$userName = $_POST["user"];
$command = 'ls -l /home/' . $userName;
system($command);

The $userName variable is not checked for malicious input. An attacker could set the $userName variable to an arbitrary OS command such as:

(attack code)

;rm -rf /

Which would result in $command being:

(result)

ls -l /home/;rm -rf /

Since the semi-colon is a command separator in Unix, the OS would first execute the ls command, then the rm command, deleting the entire file system.

Also note that this example code is vulnerable to Path Traversal (CWE-22) and Untrusted Search Path (CWE-426) attacks.

Example 2

The following simple program accepts a filename as a command line argument and displays the contents of the file back to the user. The program is installed setuid root because it is intended for use as a learning tool to allow system administrators in-training to inspect privileged system files without giving them the ability to modify them or damage the system.

(bad code)

Example Language: C

int main(int argc, char** argv) {

char cmd[CMD_MAX] = "/usr/bin/cat ";
strcat(cmd, argv[1]);
system(cmd);

}

Because the program runs with root privileges, the call to system() also executes with root privileges. If a user specifies a standard filename, the call works as expected. However, if an attacker passes a string of the form ";rm -rf /", then the call to system() fails to execute cat due to a lack of arguments and then plows on to recursively delete the contents of the root partition.

Note that if argv[1] is a very long argument, then this issue might also be subject to a buffer overflow (CWE-120).

Example 3

This example is a web application that intends to perform a DNS lookup of a user-supplied domain name. It is subject to the first variant of OS command injection.

(bad code)

Example Language: Perl

use CGI qw(:standard);
$name = param('name');
$nslookup = "/path/to/nslookup";
print header;
if (open($fh, "$nslookup $name|")) {

while (<$fh>) {

print escapeHTML($_);
print "<br>\n";

}
close($fh);

}

Suppose an attacker provides a domain name like this:

(attack code)

cwe.mitre.org%20%3B%20/bin/ls%20-l

The "%3B" sequence decodes to the ";" character, and the %20 decodes to a space. The open() statement would then process a string like this:

(result)

/path/to/nslookup cwe.mitre.org ; /bin/ls -l

As a result, the attacker executes the "/bin/ls -l" command and gets a list of all the files in the program's working directory. The input could be replaced with much more dangerous commands, such as installing a malicious program on the server.

Example 4

The example below reads the name of a shell script to execute from the system properties. It is subject to the second variant of OS command injection.

(bad code)

Example Language: Java

String script = System.getProperty("SCRIPTNAME");
if (script != null)

System.exec(script);

If an attacker has control over this property, then they could modify the property to point to a dangerous program.

Example 5

In the example below, a method is used to transform geographic coordinates from latitude and longitude format to UTM format. The method gets the input coordinates from a user through a HTTP request and executes a program local to the application server that performs the transformation. The method passes the latitude and longitude coordinates as a command-line option to the external program and will perform some processing to retrieve the results of the transformation and return the resulting UTM coordinates.

(bad code)

Example Language: Java

public String coordinateTransformLatLonToUTM(String coordinates)
{

String utmCoords = null;
try {

String latlonCoords = coordinates;
Runtime rt = Runtime.getRuntime();
Process exec = rt.exec("cmd.exe /C latlon2utm.exe -" + latlonCoords);
// process results of coordinate transform

// ...

}
catch(Exception e) {...}
return utmCoords;

}

However, the method does not verify that the contents of the coordinates input parameter includes only correctly-formatted latitude and longitude coordinates. If the input coordinates were not validated prior to the call to this method, a malicious user could execute another program local to the application server by appending '&' followed by the command for another program to the end of the coordinate string. The '&' instructs the Windows operating system to execute another program.

Example 6

The following code is from an administrative web application designed to allow users to kick off a backup of an Oracle database using a batch-file wrapper around the rman utility and then run a cleanup.bat script to delete some temporary files. The script rmanDB.bat accepts a single command line parameter, which specifies what type of backup to perform. Because access to the database is restricted, the application runs the backup as a privileged user.

(bad code)

Example Language: Java

...
String btype = request.getParameter("backuptype");
String cmd = new String("cmd.exe /K \"

c:\\util\\rmanDB.bat "
+btype+
"&&c:\\utl\\cleanup.bat\"")

System.Runtime.getRuntime().exec(cmd);
...

The problem here is that the program does not do any validation on the backuptype parameter read from the user. Typically the Runtime.exec() function will not execute multiple commands, but in this case the program first runs the cmd.exe shell in order to run multiple commands with a single call to Runtime.exec(). Once the shell is invoked, it will happily execute multiple commands separated by two ampersands. If an attacker passes a string of the form "& del c:\\dbms\\*.*", then the application will execute this command along with the others specified by the program. Because of the nature of the application, it runs with the privileges necessary to interact with the database, which means whatever command the attacker injects will run with those privileges as well.

Example 7

The following code is a wrapper around the UNIX command cat which prints the contents of a file to standard out. It is also injectable:

(bad code)

Example Language: C

#include <stdio.h>
#include <unistd.h>

int main(int argc, char **argv) {

char cat[] = "cat ";
char *command;
size_t commandLength;

commandLength = strlen(cat) + strlen(argv[1]) + 1;
command = (char *) malloc(commandLength);
strncpy(command, cat, commandLength);
strncat(command, argv[1], (commandLength - strlen(cat)) );

system(command);
return (0);

}

Used normally, the output is simply the contents of the file requested, such as Story.txt:

(informative)

./catWrapper Story.txt

(result)

When last we left our heroes...

However, if the provided argument includes a semicolon and another command, such as:

(attack code)

Story.txt; ls

Then the "ls" command is executed by catWrapper with no complaint:

(result)

./catWrapper Story.txt; ls

Two commands would then be executed: catWrapper, then ls. The result might look like:

(result)

When last we left our heroes...
Story.txt
SensitiveFile.txt
PrivateData.db
a.out*

If catWrapper had been set to have a higher privilege level than the standard user, arbitrary commands could be executed with that higher privilege.

Observed Examples

Reference	Description
CVE-2020-10987	OS command injection in Wi-Fi router, as exploited in the wild per CISA KEV.
CVE-2020-10221	Template functionality in network configuration management tool allows OS command injection, as exploited in the wild per CISA KEV.
CVE-2020-9054	Chain: improper input validation (CWE-20) in username parameter, leading to OS command injection (CWE-78), as exploited in the wild per CISA KEV.
CVE-1999-0067	Canonical example of OS command injection. CGI program does not neutralize "\|" metacharacter when invoking a phonebook program.
CVE-2001-1246	Language interpreter's mail function accepts another argument that is concatenated to a string used in a dangerous popen() call. Since there is no neutralization of this argument, both OS Command Injection (CWE-78) and Argument Injection (CWE-88) are possible.
CVE-2002-0061	Web server allows command execution using "\|" (pipe) character.
CVE-2003-0041	FTP client does not filter "\|" from filenames returned by the server, allowing for OS command injection.
CVE-2008-2575	Shell metacharacters in a filename in a ZIP archive
CVE-2002-1898	Shell metacharacters in a telnet:// link are not properly handled when the launching application processes the link.
CVE-2008-4304	OS command injection through environment variable.
CVE-2008-4796	OS command injection through https:// URLs
CVE-2007-3572	Chain: incomplete denylist for OS command injection
CVE-2012-1988	Product allows remote users to execute arbitrary commands by creating a file whose pathname contains shell metacharacters.

Detection Methods

Automated Static Analysis

This weakness can often be detected using automated static analysis tools. Many modern tools use data flow analysis or constraint-based techniques to minimize the number of false positives.

Automated static analysis might not be able to recognize when proper input validation is being performed, leading to false positives - i.e., warnings that do not have any security consequences or require any code changes.

Automated static analysis might not be able to detect the usage of custom API functions or third-party libraries that indirectly invoke OS commands, leading to false negatives - especially if the API/library code is not available for analysis.

Note: This is not a perfect solution, since 100% accuracy and coverage are not feasible.

Automated Dynamic Analysis

This weakness can be detected using dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

Effectiveness: Moderate

Manual Static Analysis

Since this weakness does not typically appear frequently within a single software package, manual white box techniques may be able to provide sufficient code coverage and reduction of false positives if all potentially-vulnerable operations can be assessed within limited time constraints.

Effectiveness: High

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Bytecode Weakness Analysis - including disassembler + source code weakness analysis

Binary Weakness Analysis - including disassembler + source code weakness analysis

Effectiveness: High

Dynamic Analysis with Automated Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Web Application Scanner

Web Services Scanner

Database Scanners

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Fuzz Tester

Framework-based Fuzzer

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Manual Source Code Review (not inspections)

Cost effective for partial coverage:

Focused Manual Spotcheck - Focused manual analysis of source

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Source code Weakness Analyzer

Context-configured Source Code Weakness Analyzer

Effectiveness: High

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Effectiveness: High

Functional Areas

Program Invocation

Affected Resources

System Process

Memberships

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	635	Weaknesses Originally Used by NVD from 2008 to 2016
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	714	OWASP Top Ten 2007 Category A3 - Malicious File Execution
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	727	OWASP Top Ten 2004 Category A6 - Injection Flaws
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	741	CERT C Secure Coding Standard (2008) Chapter 8 - Characters and Strings (STR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	744	CERT C Secure Coding Standard (2008) Chapter 11 - Environment (ENV)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	751	2009 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	801	2010 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	810	OWASP Top Ten 2010 Category A1 - Injection
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	845	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 2 - Input Validation and Data Sanitization (IDS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	864	2011 Top 25 - Insecure Interaction Between Components
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	875	CERT C++ Secure Coding Section 07 - Characters and Strings (STR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	878	CERT C++ Secure Coding Section 10 - Environment (ENV)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	929	OWASP Top Ten 2013 Category A1 - Injection
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	990	SFP Secondary Cluster: Tainted Input to Command
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1027	OWASP Top Ten 2017 Category A1 - Injection
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1131	CISQ Quality Measures (2016) - Security
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1134	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 00. Input Validation and Data Sanitization (IDS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1165	SEI CERT C Coding Standard - Guidelines 10. Environment (ENV)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1200	Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1337	Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1347	OWASP Top Ten 2021 Category A03:2021 - Injection
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1350	Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1387	Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1409	Comprehensive Categorization: Injection
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1425	Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Terminology

The "OS command injection" phrase carries different meanings to different people. For some people, it only refers to cases in which the attacker injects command separators into arguments for an application-controlled program that is being invoked. For some people, it refers to any type of attack that can allow the attacker to execute OS commands of their own choosing. This usage could include untrusted search path weaknesses (CWE-426) that cause the application to find and execute an attacker-controlled program. Further complicating the issue is the case when argument injection (CWE-88) allows alternate command-line switches or options to be inserted into the command line, such as an "-exec" switch whose purpose may be to execute the subsequent argument as a command (this -exec switch exists in the UNIX "find" command, for example). In this latter case, however, CWE-88 could be regarded as the primary weakness in a chain with CWE-78.

Research Gap

More investigation is needed into the distinction between the OS command injection variants, including the role with argument injection (CWE-88). Equivalent distinctions may exist in other injection-related problems such as SQL injection.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
PLOVER			OS Command Injection
OWASP Top Ten 2007	A3	CWE More Specific	Malicious File Execution
OWASP Top Ten 2004	A6	CWE More Specific	Injection Flaws
CERT C Secure Coding	ENV03-C		Sanitize the environment when invoking external programs
CERT C Secure Coding	ENV33-C	CWE More Specific	Do not call system()
CERT C Secure Coding	STR02-C		Sanitize data passed to complex subsystems
WASC	31		OS Commanding
The CERT Oracle Secure Coding Standard for Java (2011)	IDS07-J		Do not pass untrusted, unsanitized data to the Runtime.exec() method
Software Fault Patterns	SFP24		Tainted input to command
OMG ASCSM	ASCSM-CWE-78

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-108	Command Line Execution through SQL Injection
CAPEC-15	Command Delimiters
CAPEC-43	Exploiting Multiple Input Interpretation Layers
CAPEC-6	Argument Injection
CAPEC-88	OS Command Injection

References

[REF-140] Greg Hoglund and Gary McGraw. "Exploiting Software: How to Break Code". Addison-Wesley. 2004-02-27. <https://www.amazon.com/Exploiting-Software-How-Break-Code/dp/0201786958>. URL validated: 2023-04-07.

[REF-685] Pascal Meunier. "Meta-Character Vulnerabilities". 2008-02-20. <https://web.archive.org/web/20100714032622/https://www.cs.purdue.edu/homes/cs390s/slides/week09.pdf>. URL validated: 2023-04-07.

[REF-686] Robert Auger. "OS Commanding". 2009-06. <http://projects.webappsec.org/w/page/13246950/OS%20Commanding>. URL validated: 2023-04-07.

[REF-687] Lincoln Stein and John Stewart. "The World Wide Web Security FAQ". chapter: "CGI Scripts". 2002-02-04. <https://www.w3.org/Security/Faq/wwwsf4.html>. URL validated: 2023-04-07.

[REF-688] Jordan Dimov, Cigital. "Security Issues in Perl Scripts". <https://www.cgisecurity.com/lib/sips.html>. URL validated: 2023-04-07.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 10: Command Injection." Page 171. McGraw-Hill. 2010.

[REF-690] Frank Kim. "Top 25 Series - Rank 9 - OS Command Injection". SANS Software Security Institute. 2010-02-24. <https://www.sans.org/blog/top-25-series-rank-9-os-command-injection/>. URL validated: 2023-04-07.

[REF-45] OWASP. "OWASP Enterprise Security API (ESAPI) Project". <http://www.owasp.org/index.php/ESAPI>.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 8, "Shell Metacharacters", Page 425. 1st Edition. Addison Wesley. 2006.

[REF-962] Object Management Group (OMG). "Automated Source Code Security Measure (ASCSM)". ASCSM-CWE-78. 2016-01. <http://www.omg.org/spec/ASCSM/1.0/>.

[REF-1449] Cybersecurity and Infrastructure Security Agency. "Secure by Design Alert: Eliminating OS Command Injection Vulnerabilities". 2024-07-10. <https://www.cisa.gov/resources-tools/resources/secure-design-alert-eliminating-os-command-injection-vulnerabilities>. URL validated: 2024-07-14.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	PLOVER
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2024-02-29 (CWE 4.15, 2024-07-16)	Abhi Balakrishnan
2024-02-29 (CWE 4.15, 2024-07-16)	Provided diagram to improve CWE usability
Modifications
Modification Date	Modifier	Organization
2008-07-01	Sean Eidemiller	Cigital
2008-07-01	added/updated demonstrative examples
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-08-01		KDM Analytics
2008-08-01	added/updated white box definitions
2008-08-15		Veracode
2008-08-15	Suggested OWASP Top Ten 2004 mapping
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships, Other_Notes, Taxonomy_Mappings
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Description
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Observed_Examples, Relationships, Taxonomy_Mappings
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Common_Consequences, Demonstrative_Examples, Description, Likelihood_of_Exploit, Name, Observed_Examples, Other_Notes, Potential_Mitigations, Relationships, Research_Gaps, Terminology_Notes
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Name, Related_Attack_Patterns
2009-07-17	KDM Analytics
2009-07-17	Improved the White_Box_Definition
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Description, Name, White_Box_Definitions
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Observed_Examples, References
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Detection_Factors
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Detection_Factors, Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Potential_Mitigations
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, Description, Detection_Factors, Name, Observed_Examples, Potential_Mitigations, References, Relationships
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Potential_Mitigations
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Description, Potential_Mitigations
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Demonstrative_Examples, Description
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, References, Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Observed_Examples, Potential_Mitigations
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Applicable_Platforms, Demonstrative_Examples, Terminology_Notes
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Detection_Factors, Relationships, Taxonomy_Mappings
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Modes_of_Introduction, References, Relationships, Taxonomy_Mappings, White_Box_Definitions
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated Relationships
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated References, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Potential_Mitigations, Relationships
2020-06-25	CWE Content Team	MITRE
2020-06-25	updated Observed_Examples, Potential_Mitigations
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Potential_Mitigations, Relationships
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Observed_Examples, Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-04-28	CWE Content Team	MITRE
2022-04-28	updated Demonstrative_Examples
2022-06-28	CWE Content Team	MITRE
2022-06-28	updated Observed_Examples, Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated References
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Common_Consequences, Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, References, Relationships, Time_of_Introduction
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
2024-07-16 (CWE 4.15, 2024-07-16)	CWE Content Team	MITRE
2024-07-16 (CWE 4.15, 2024-07-16)	updated Alternate_Terms, Common_Consequences, Demonstrative_Examples, Description, Diagram, References
Previous Entry Names
Change Date	Previous Entry Name
2008-04-11	OS Command Injection

2009-01-12	Failure to Sanitize Data into an OS Command (aka 'OS Command Injection')

2009-05-27	Failure to Preserve OS Command Structure (aka 'OS Command Injection')

2009-07-27	Failure to Preserve OS Command Structure ('OS Command Injection')

2010-06-21	Improper Sanitization of Special Elements used in an OS Command ('OS Command Injection')

Weakness ID: 404

View customized information:

Description

The product does not release or incorrectly releases a resource before it is made available for re-use.

Extended Description

When a resource is created or allocated, the developer is responsible for properly releasing the resource as well as accounting for all potential paths of expiration or invalidation, such as a set period of time or revocation.

Common Consequences

Scope	Impact	Likelihood
Availability Other	Technical Impact: DoS: Resource Consumption (Other); Varies by Context Most unreleased resource issues result in general software reliability problems, but if an attacker can intentionally trigger a resource leak, the attacker might be able to launch a denial of service attack by depleting the resource pool.
Confidentiality	Technical Impact: Read Application Data When a resource containing sensitive information is not correctly shutdown, it may expose the sensitive data in a subsequent allocation.

Potential Mitigations

Phase: Requirements

Strategy: Language Selection

Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

For example, languages such as Java, Ruby, and Lisp perform automatic garbage collection that releases memory for objects that have been deallocated.

Phase: Implementation

It is good practice to be responsible for freeing all resources you allocate and to be consistent with how and where you free memory in a function. If you allocate memory that you intend to free upon completion of the function, you must be sure to free the memory at all exit points for that function including error conditions.

Phase: Implementation

Memory should be allocated/freed using matching functions such as malloc/free, new/delete, and new[]/delete[].

Phase: Implementation

When releasing a complex object or structure, ensure that you properly dispose of all of its member components, not just the object itself.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	664	Improper Control of a Resource Through its Lifetime
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	299	Improper Check for Certificate Revocation
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	459	Incomplete Cleanup
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	763	Release of Invalid Pointer or Reference
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	772	Missing Release of Resource after Effective Lifetime
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1266	Improper Scrubbing of Sensitive Data from Decommissioned Device
PeerOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	405	Asymmetric Resource Consumption (Amplification)
PeerOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	239	Failure to Handle Incomplete Element
CanPrecede	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	619	Dangling Database Cursor ('Cursor Injection')

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	401	Missing Release of Memory after Effective Lifetime
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	459	Incomplete Cleanup
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	763	Release of Invalid Pointer or Reference
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	772	Missing Release of Resource after Effective Lifetime

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	401	Missing Release of Memory after Effective Lifetime
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	772	Missing Release of Resource after Effective Lifetime
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	775	Missing Release of File Descriptor or Handle after Effective Lifetime

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	761	Free of Pointer not at Start of Buffer
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	762	Mismatched Memory Management Routines
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	763	Release of Invalid Pointer or Reference
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	772	Missing Release of Resource after Effective Lifetime
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	775	Missing Release of File Descriptor or Handle after Effective Lifetime

Modes Of Introduction

Phase	Note
Implementation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

The following method never closes the new file handle. Given enough time, the Finalize() method for BufferReader should eventually call Close(), but there is no guarantee as to how long this action will take. In fact, there is no guarantee that Finalize() will ever be invoked. In a busy environment, the Operating System could use up all of the available file handles before the Close() function is called.

(bad code)

Example Language: Java

private void processFile(string fName)
{

BufferReader fil = new BufferReader(new FileReader(fName));
String line;
while ((line = fil.ReadLine()) != null)
{

processLine(line);

}

The good code example simply adds an explicit call to the Close() function when the system is done using the file. Within a simple example such as this the problem is easy to see and fix. In a real system, the problem may be considerably more obscure.

(good code)

Example Language: Java

private void processFile(string fName)
{

BufferReader fil = new BufferReader(new FileReader(fName));
String line;
while ((line = fil.ReadLine()) != null)
{

processLine(line);

}
fil.Close();

}

Example 2

This code attempts to open a connection to a database and catches any exceptions that may occur.

(bad code)

Example Language: Java

try {

Connection con = DriverManager.getConnection(some_connection_string);

}
catch ( Exception e ) {

log( e );

}

If an exception occurs after establishing the database connection and before the same connection closes, the pool of database connections may become exhausted. If the number of available connections is exceeded, other users cannot access this resource, effectively denying access to the application.

Example 3

Under normal conditions the following C# code executes a database query, processes the results returned by the database, and closes the allocated SqlConnection object. But if an exception occurs while executing the SQL or processing the results, the SqlConnection object is not closed. If this happens often enough, the database will run out of available cursors and not be able to execute any more SQL queries.

(bad code)

Example Language: C#

...
SqlConnection conn = new SqlConnection(connString);
SqlCommand cmd = new SqlCommand(queryString);
cmd.Connection = conn;
conn.Open();
SqlDataReader rdr = cmd.ExecuteReader();
HarvestResults(rdr);
conn.Connection.Close();
...

Example 4

The following C function does not close the file handle it opens if an error occurs. If the process is long-lived, the process can run out of file handles.

(bad code)

Example Language: C

int decodeFile(char* fName) {

char buf[BUF_SZ];
FILE* f = fopen(fName, "r");
if (!f) {

printf("cannot open %s\n", fName);
return DECODE_FAIL;

}
else {

while (fgets(buf, BUF_SZ, f)) {

if (!checkChecksum(buf)) {

return DECODE_FAIL;

}
else {

decodeBlock(buf);

}

}
fclose(f);
return DECODE_SUCCESS;

}

Example 5

In this example, the program does not use matching functions such as malloc/free, new/delete, and new[]/delete[] to allocate/deallocate the resource.

(bad code)

Example Language: C++

class A {

void foo();

};
void A::foo(){

int *ptr;
ptr = (int*)malloc(sizeof(int));
delete ptr;

}

Example 6

In this example, the program calls the delete[] function on non-heap memory.

(bad code)

Example Language: C++

class A{

void foo(bool);

};
void A::foo(bool heap) {

int localArray[2] = {

11,22

};
int *p = localArray;
if (heap){

p = new int[2];

}
delete[] p;

}

Observed Examples

Reference	Description
CVE-1999-1127	Does not shut down named pipe connections if malformed data is sent.
CVE-2001-0830	Sockets not properly closed when attacker repeatedly connects and disconnects from server.
CVE-2002-1372	Chain: Return values of file/socket operations are not checked (CWE-252), allowing resultant consumption of file descriptors (CWE-772).

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness is a quality issue that might indirectly make it easier to introduce security-relevant weaknesses or make them more difficult to detect) Improper release or shutdown of resources can be primary to resource exhaustion, performance, and information confidentiality problems to name a few.
Resultant	(where the weakness is a quality issue that might indirectly make it easier to introduce security-relevant weaknesses or make them more difficult to detect) Improper release or shutdown of resources can be resultant from improper error handling or insufficient resource tracking.

Detection Methods

Automated Dynamic Analysis

Resource clean up errors might be detected with a stress-test by calling the software simultaneously from a large number of threads or processes, and look for evidence of any unexpected behavior. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.

Effectiveness: Moderate

Manual Dynamic Analysis

Identify error conditions that are not likely to occur during normal usage and trigger them. For example, run the product under low memory conditions, run with insufficient privileges or permissions, interrupt a transaction before it is completed, or disable connectivity to basic network services such as DNS. Monitor the software for any unexpected behavior. If you trigger an unhandled exception or similar error that was discovered and handled by the application's environment, it may still indicate unexpected conditions that were not handled by the application itself.

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	398	7PK - Code Quality
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	730	OWASP Top Ten 2004 Category A9 - Denial of Service
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	743	CERT C Secure Coding Standard (2008) Chapter 10 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	752	2009 Top 25 - Risky Resource Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	857	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	876	CERT C++ Secure Coding Section 08 - Memory Management (MEM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	877	CERT C++ Secure Coding Section 09 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	882	CERT C++ Secure Coding Section 14 - Concurrency (CON)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	982	SFP Secondary Cluster: Failure to Release Resource
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1147	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 13. Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1162	SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1163	SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1306	CISQ Quality Measures - Reliability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1309	CISQ Quality Measures - Efficiency
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1416	Comprehensive Categorization: Resource Lifecycle Management

Vulnerability Mapping Notes

Usage: ALLOWED-WITH-REVIEW

(this CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review)

Reason: Abstraction

Rationale:

This CWE entry is a Class and might have Base-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit

Notes

Relationship

Overlaps memory leaks, asymmetric resource consumption, malformed input errors.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
PLOVER			Improper resource shutdown or release
7 Pernicious Kingdoms			Unreleased Resource
OWASP Top Ten 2004	A9	CWE More Specific	Denial of Service
CERT C Secure Coding	FIO42-C	CWE More Abstract	Close files when they are no longer needed
CERT C Secure Coding	MEM31-C	CWE More Abstract	Free dynamically allocated memory when no longer needed
The CERT Oracle Secure Coding Standard for Java (2011)	FIO04-J		Release resources when they are no longer needed
Software Fault Patterns	SFP14		Failure to release resource

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-125	Flooding
CAPEC-130	Excessive Allocation
CAPEC-131	Resource Leak Exposure
CAPEC-494	TCP Fragmentation
CAPEC-495	UDP Fragmentation
CAPEC-496	ICMP Fragmentation
CAPEC-666	BlueSmacking

References

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 8: C++ Catastrophes." Page 143. McGraw-Hill. 2010.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	PLOVER
2006-07-19 (CWE Draft 3, 2006-07-19)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-08-15		Veracode
2008-08-15	Suggested OWASP Top Ten 2004 mapping
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Description, Relationships, Other_Notes, Taxonomy_Mappings
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Relationships
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Relationships, Taxonomy_Mappings
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Common_Consequences, Likelihood_of_Exploit, Other_Notes, Potential_Mitigations, Relationship_Notes, Relationships, Weakness_Ordinalities
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Description, Relationships
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Demonstrative_Examples, Related_Attack_Patterns
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Other_Notes
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Potential_Mitigations, Relationships
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Detection_Factors, Potential_Mitigations
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Demonstrative_Examples
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Weakness_Ordinalities
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Common_Consequences
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, References, Relationships, Taxonomy_Mappings
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Demonstrative_Examples
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Related_Attack_Patterns
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Relationships
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Relationships
2017-05-03	CWE Content Team	MITRE
2017-05-03	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, Functional_Areas, Likelihood_of_Exploit, Relationships, Taxonomy_Mappings
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings, Type
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Related_Attack_Patterns, Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Relationships
2020-06-25	CWE Content Team	MITRE
2020-06-25	updated Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Demonstrative_Examples
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Related_Attack_Patterns
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description, Detection_Factors
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, Relationships, Time_of_Introduction
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2023-10-26	CWE Content Team	MITRE
2023-10-26	updated Observed_Examples

Weakness ID: 662

View customized information:

Description

Extended Description

Synchronization refers to a variety of behaviors and mechanisms that allow two or more independently-operating processes or threads to ensure that they operate on shared resources in predictable ways that do not interfere with each other. Some shared resource operations cannot be executed atomically; that is, multiple steps must be guaranteed to execute sequentially, without any interference by other processes. Synchronization mechanisms vary widely, but they may include locking, mutexes, and semaphores. When a multi-step operation on a shared resource cannot be guaranteed to execute independent of interference, then the resulting behavior can be unpredictable. Improper synchronization could lead to data or memory corruption, denial of service, etc.

Common Consequences

Scope	Impact	Likelihood
Integrity Confidentiality Other	Technical Impact: Modify Application Data; Read Application Data; Alter Execution Logic

Potential Mitigations

Phase: Implementation

Use industry standard APIs to synchronize your code.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	691	Insufficient Control Flow Management
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	664	Improper Control of a Resource Through its Lifetime
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	663	Use of a Non-reentrant Function in a Concurrent Context
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	667	Improper Locking
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	820	Missing Synchronization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	821	Incorrect Synchronization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1058	Invokable Control Element in Multi-Thread Context with non-Final Static Storable or Member Element
CanPrecede	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	362	Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	667	Improper Locking

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	366	Race Condition within a Thread
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	543	Use of Singleton Pattern Without Synchronization in a Multithreaded Context
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	567	Unsynchronized Access to Shared Data in a Multithreaded Context
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	667	Improper Locking
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	764	Multiple Locks of a Critical Resource
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	820	Missing Synchronization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	821	Incorrect Synchronization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	833	Deadlock
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1058	Invokable Control Element in Multi-Thread Context with non-Final Static Storable or Member Element
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	1096	Singleton Class Instance Creation without Proper Locking or Synchronization

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	366	Race Condition within a Thread
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	543	Use of Singleton Pattern Without Synchronization in a Multithreaded Context
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	567	Unsynchronized Access to Shared Data in a Multithreaded Context
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	667	Improper Locking
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	764	Multiple Locks of a Critical Resource
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	820	Missing Synchronization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	821	Incorrect Synchronization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1058	Invokable Control Element in Multi-Thread Context with non-Final Static Storable or Member Element
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	1096	Singleton Class Instance Creation without Proper Locking or Synchronization

Modes Of Introduction

Phase	Note
Architecture and Design
Implementation

Demonstrative Examples

Example 1

The following function attempts to acquire a lock in order to perform operations on a shared resource.

(bad code)

Example Language: C

void f(pthread_mutex_t *mutex) {

pthread_mutex_lock(mutex);

/* access shared resource */

pthread_mutex_unlock(mutex);

}

(good code)

Example Language: C

int f(pthread_mutex_t *mutex) {

int result;

result = pthread_mutex_lock(mutex);
if (0 != result)

return result;

/* access shared resource */

return pthread_mutex_unlock(mutex);

}

Example 2

The following code intends to fork a process, then have both the parent and child processes print a single line.

(bad code)

Example Language: C

static void print (char * string) {

char * word;
int counter;
for (word = string; counter = *word++; ) {

putc(counter, stdout);
fflush(stdout);
/* Make timing window a little larger... */

sleep(1);

}

}

int main(void) {

pid_t pid;

pid = fork();
if (pid == -1) {

exit(-2);

}
else if (pid == 0) {

print("child\n");

}
else {

print("PARENT\n");

}
exit(0);

}

One might expect the code to print out something like:

PARENT

child

However, because the parent and child are executing concurrently, and stdout is flushed each time a character is printed, the output might be mixed together, such as:

PcAhRiElNdT

[blank line]

Observed Examples

Reference	Description
CVE-2021-1782	Chain: improper locking (CWE-667) leads to race condition (CWE-362), as exploited in the wild per CISA KEV.
CVE-2009-0935	Attacker provides invalid address to a memory-reading function, causing a mutex to be unlocked twice

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	745	CERT C Secure Coding Standard (2008) Chapter 12 - Signals (SIG)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	852	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 9 - Visibility and Atomicity (VNA)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	879	CERT C++ Secure Coding Section 11 - Signals (SIG)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	986	SFP Secondary Cluster: Missing Lock
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1142	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 08. Visibility and Atomicity (VNA)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1166	SEI CERT C Coding Standard - Guidelines 11. Signals (SIG)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1306	CISQ Quality Measures - Reliability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1416	Comprehensive Categorization: Resource Lifecycle Management

Vulnerability Mapping Notes

Usage: DISCOURAGED

(this CWE ID should not be used to map to real-world vulnerabilities)

Reason: Abstraction

Rationale:

This CWE entry is a level-1 Class (i.e., a child of a Pillar). It might have lower-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit

Notes

Maintenance

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
CERT C Secure Coding	SIG00-C		Mask signals handled by noninterruptible signal handlers
CERT C Secure Coding	SIG31-C	CWE More Abstract	Do not access shared objects in signal handlers
CLASP			State synchronization error
The CERT Oracle Secure Coding Standard for Java (2011)	VNA03-J		Do not assume that a group of calls to independently atomic methods is atomic
Software Fault Patterns	SFP19		Missing Lock

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-25	Forced Deadlock
CAPEC-26	Leveraging Race Conditions
CAPEC-27	Leveraging Race Conditions via Symbolic Links
CAPEC-29	Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions

Content History

Submissions
Submission Date	Submitter	Organization
2008-04-11 (CWE Draft 9, 2008-04-11)	CWE Community
2008-04-11 (CWE Draft 9, 2008-04-11)	Submitted by members of the CWE community to extend early CWE versions
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Potential_Mitigations, Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Relationships
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Relationships, Taxonomy_Mappings
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Related_Attack_Patterns
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Relationships
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Name, Relationships
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Description, Relationships, Taxonomy_Mappings
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Relationships
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2013-07-17	CWE Content Team	MITRE
2013-07-17	updated Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Taxonomy_Mappings
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Type
2019-09-23	CWE Content Team	MITRE
2019-09-23	updated Description, Maintenance_Notes, Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Description, Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2023-10-26	CWE Content Team	MITRE
2023-10-26	updated Demonstrative_Examples, Observed_Examples
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2010-09-27	Insufficient Synchronization

Weakness ID: 681

View customized information:

Description

Common Consequences

Scope	Impact	Likelihood
Other Integrity	Technical Impact: Unexpected State; Quality Degradation The program could wind up using the wrong number and generate incorrect results. If the number is used to allocate resources or make a security decision, then this could introduce a vulnerability.

Potential Mitigations

Phase: Implementation

Avoid making conversion between numeric types. Always check for the allowed ranges.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	704	Incorrect Type Conversion or Cast
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	192	Integer Coercion Error
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	194	Unexpected Sign Extension
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	195	Signed to Unsigned Conversion Error
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	196	Unsigned to Signed Conversion Error
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	197	Numeric Truncation Error
CanPrecede	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	682	Incorrect Calculation

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	136	Type Errors
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	189	Numeric Errors

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	704	Incorrect Type Conversion or Cast

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	194	Unexpected Sign Extension
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	195	Signed to Unsigned Conversion Error
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	196	Unsigned to Signed Conversion Error
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	197	Numeric Truncation Error

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	194	Unexpected Sign Extension
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	195	Signed to Unsigned Conversion Error
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	196	Unsigned to Signed Conversion Error
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	197	Numeric Truncation Error

Modes Of Introduction

Phase	Note
Implementation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

In the following Java example, a float literal is cast to an integer, thus causing a loss of precision.

(bad code)

Example Language: Java

int i = (int) 33457.8f;

Example 2

This code adds a float and an integer together, casting the result to an integer.

(bad code)

Example Language: PHP

$floatVal = 1.8345;
$intVal = 3;
$result = (int)$floatVal + $intVal;

Normally, PHP will preserve the precision of this operation, making $result = 4.8345. After the cast to int, it is reasonable to expect PHP to follow rounding convention and set $result = 5. However, the explicit cast to int always rounds DOWN, so the final value of $result is 4. This behavior may have unintended consequences.

Example 3

In this example the variable amount can hold a negative value when it is returned. Because the function is declared to return an unsigned int, amount will be implicitly converted to unsigned.

(bad code)

Example Language: C

unsigned int readdata () {

int amount = 0;
...
if (result == ERROR)
amount = -1;
...
return amount;

}

If the error condition in the code above is met, then the return value of readdata() will be 4,294,967,295 on a system that uses 32-bit integers.

Example 4

In this example, depending on the return value of accecssmainframe(), the variable amount can hold a negative value when it is returned. Because the function is declared to return an unsigned value, amount will be implicitly cast to an unsigned number.

(bad code)

Example Language: C

unsigned int readdata () {

int amount = 0;
...
amount = accessmainframe();
...
return amount;

}

If the return value of accessmainframe() is -1, then the return value of readdata() will be 4,294,967,295 on a system that uses 32-bit integers.

Observed Examples

Reference	Description
CVE-2022-2639	Chain: integer coercion error (CWE-192) prevents a return value from indicating an error, leading to out-of-bounds write (CWE-787)
CVE-2021-43537	Chain: in a web browser, an unsigned 64-bit integer is forcibly cast to a 32-bit integer (CWE-681) and potentially leading to an integer overflow (CWE-190). If an integer overflow occurs, this can cause heap memory corruption (CWE-122)
CVE-2007-4268	Chain: integer signedness error (CWE-195) passes signed comparison, leading to heap overflow (CWE-122)
CVE-2007-4988	Chain: signed short width value in image processor is sign extended during conversion to unsigned int, which leads to integer overflow and heap-based buffer overflow.
CVE-2009-0231	Integer truncation of length value leads to heap-based buffer overflow.
CVE-2008-3282	Size of a particular type changes for 64-bit platforms, leading to an integer truncation in document processor causes incorrect index to be generated.

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	738	CERT C Secure Coding Standard (2008) Chapter 5 - Integers (INT)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	739	CERT C Secure Coding Standard (2008) Chapter 6 - Floating Point (FLP)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	808	2010 Top 25 - Weaknesses On the Cusp
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	848	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 5 - Numeric Types and Operations (NUM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	867	2011 Top 25 - Weaknesses On the Cusp
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	872	CERT C++ Secure Coding Section 04 - Integers (INT)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	873	CERT C++ Secure Coding Section 05 - Floating Point Arithmetic (FLP)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	998	SFP Secondary Cluster: Glitch in Computation
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1131	CISQ Quality Measures (2016) - Security
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1137	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 03. Numeric Types and Operations (NUM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1158	SEI CERT C Coding Standard - Guidelines 04. Integers (INT)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1159	SEI CERT C Coding Standard - Guidelines 05. Floating Point (FLP)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1306	CISQ Quality Measures - Reliability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1416	Comprehensive Categorization: Resource Lifecycle Management

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
CERT C Secure Coding	FLP34-C	CWE More Abstract	Ensure that floating point conversions are within range of the new type
CERT C Secure Coding	INT15-C		Use intmax_t or uintmax_t for formatted IO on programmer-defined integer types
CERT C Secure Coding	INT31-C	CWE More Abstract	Ensure that integer conversions do not result in lost or misinterpreted data
CERT C Secure Coding	INT35-C		Evaluate integer expressions in a larger size before comparing or assigning to that size
The CERT Oracle Secure Coding Standard for Java (2011)	NUM12-J		Ensure conversions of numeric types to narrower types do not result in lost or misinterpreted data
Software Fault Patterns	SFP1		Glitch in computation
OMG ASCSM	ASCSM-CWE-681

References

[REF-962] Object Management Group (OMG). "Automated Source Code Security Measure (ASCSM)". ASCSM-CWE-681. 2016-01. <http://www.omg.org/spec/ASCSM/1.0/>.

Content History

Submissions
Submission Date	Submitter	Organization
2008-04-11 (CWE Draft 9, 2008-04-11)	CWE Community
2008-04-11 (CWE Draft 9, 2008-04-11)	Submitted by members of the CWE community to extend early CWE versions
Modifications
Modification Date	Modifier	Organization
2008-07-01	Sean Eidemiller	Cigital
2008-07-01	added/updated demonstrative examples
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Potential_Mitigations, Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Relationships
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Description, Relationships, Taxonomy_Mappings
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Applicable_Platforms, Likelihood_of_Exploit, Potential_Mitigations
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Relationships
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Demonstrative_Examples
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Common_Consequences, Observed_Examples, Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, References, Relationships, Taxonomy_Mappings
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Likelihood_of_Exploit, Observed_Examples, Taxonomy_Mappings, Type
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated References, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships, Type
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Relationships
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2023-10-26	CWE Content Team	MITRE
2023-10-26	updated Observed_Examples
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Observed_Examples

Weakness ID: 732

View customized information:

Description

The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.

Extended Description

When a resource is given a permission setting that provides access to a wider range of actors than required, it could lead to the exposure of sensitive information, or the modification of that resource by unintended parties. This is especially dangerous when the resource is related to program configuration, execution, or sensitive user data. For example, consider a misconfigured storage account for the cloud that can be read or written by a public or anonymous user.

Common Consequences

Scope	Impact	Likelihood
Confidentiality	Technical Impact: Read Application Data; Read Files or Directories An attacker may be able to read sensitive information from the associated resource, such as credentials or configuration information stored in a file.
Access Control	Technical Impact: Gain Privileges or Assume Identity An attacker may be able to modify critical properties of the associated resource to gain privileges, such as replacing a world-writable executable with a Trojan horse.
Integrity Other	Technical Impact: Modify Application Data; Other An attacker may be able to destroy or corrupt critical data in the associated resource, such as deletion of records from a database.

Potential Mitigations

Phase: Implementation

When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user) [REF-62], and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.

Phase: Architecture and Design

Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly. This will allow you to maintain more fine-grained control over your resources. [REF-207]

Effectiveness: Moderate

Note: This can be an effective strategy. However, in practice, it may be difficult or time consuming to define these areas when there are many different resources or user types, or if the applications features change rapidly.

Phases: Architecture and Design; Operation

Strategy: Sandbox or Jail

This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.

Be careful to avoid CWE-243 and other weaknesses related to jails.

Effectiveness: Limited

Phases: Implementation; Installation

During program startup, explicitly set the default permissions or umask to the most restrictive setting possible. Also set the appropriate permissions during program installation. This will prevent you from inheriting insecure permissions from any user who installs or runs the program.

Effectiveness: High

Phase: System Configuration

For all configuration files, executables, and libraries, make sure that they are only readable and writable by the software's administrator.

Effectiveness: High

Phase: Documentation

Do not suggest insecure configuration changes in documentation, especially if those configurations can extend to resources and other programs that are outside the scope of the application.

Phase: Installation

Do not assume that a system administrator will manually change the configuration to the settings that are recommended in the software's manual.

Phases: Operation; System Configuration

Strategy: Environment Hardening

Phases: Implementation; System Configuration; Operation

When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to disable public access.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	668	Exposure of Resource to Wrong Sphere
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	285	Improper Authorization
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	276	Incorrect Default Permissions
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	277	Insecure Inherited Permissions
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	278	Insecure Preserved Inherited Permissions
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	279	Incorrect Execution-Assigned Permissions
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	281	Improper Preservation of Permissions
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	766	Critical Data Element Declared Public
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	1004	Sensitive Cookie Without 'HttpOnly' Flag

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	276	Incorrect Default Permissions
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	281	Improper Preservation of Permissions

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1011	Authorize Actors

Modes Of Introduction

Phase	Note
Architecture and Design
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic. The developer might make certain assumptions about the environment in which the product operates - e.g., that the software is running on a single-user system, or the software is only accessible to trusted administrators. When the software is running in a different environment, the permissions become a problem.
Installation	The developer may set loose permissions in order to minimize problems when the user first runs the program, then create documentation stating that permissions should be tightened. Since system administrators and users do not always read the documentation, this can result in insecure permissions being left unchanged.
Operation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: Not Technology-Specific (Undetermined Prevalence)

Class: Cloud Computing (Often Prevalent)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

The following code sets the umask of the process to 0 before creating a file and writing "Hello world" into the file.

(bad code)

Example Language: C

#define OUTFILE "hello.out"

umask(0);
FILE *out;
/* Ignore link following (CWE-59) for brevity */

out = fopen(OUTFILE, "w");
if (out) {

fprintf(out, "hello world!\n");
fclose(out);

}

After running this program on a UNIX system, running the "ls -l" command might return the following output:

(result)

-rw-rw-rw- 1 username 13 Nov 24 17:58 hello.out

The "rw-rw-rw-" string indicates that the owner, group, and world (all users) can read the file and write to it.

Example 2

This code creates a home directory for a new user, and makes that user the owner of the directory. If the new directory cannot be owned by the user, the directory is deleted.

(bad code)

Example Language: PHP

function createUserDir($username){

$path = '/home/'.$username;
if(!mkdir($path)){

return false;

}
if(!chown($path,$username)){

rmdir($path);
return false;

}
return true;

}

Because the optional "mode" argument is omitted from the call to mkdir(), the directory is created with the default permissions 0777. Simply setting the new user as the owner of the directory does not explicitly change the permissions of the directory, leaving it with the default. This default allows any user to read and write to the directory, allowing an attack on the user's files. The code also fails to change the owner group of the directory, which may result in access by unexpected groups.

This code may also be vulnerable to Path Traversal (CWE-22) attacks if an attacker supplies a non alphanumeric username.

Example 3

The following code snippet might be used as a monitor to periodically record whether a web site is alive. To ensure that the file can always be modified, the code uses chmod() to make the file world-writable.

(bad code)

Example Language: Perl

$fileName = "secretFile.out";

if (-e $fileName) {

chmod 0777, $fileName;

}

my $outFH;
if (! open($outFH, ">>$fileName")) {

ExitError("Couldn't append to $fileName: $!");

}
my $dateString = FormatCurrentTime();
my $status = IsHostAlive("cwe.mitre.org");
print $outFH "$dateString cwe status: $status!\n";
close($outFH);

The first time the program runs, it might create a new file that inherits the permissions from its environment. A file listing might look like:

(result)

-rw-r--r-- 1 username 13 Nov 24 17:58 secretFile.out

This listing might occur when the user has a default umask of 022, which is a common setting. Depending on the nature of the file, the user might not have intended to make it readable by everyone on the system.

The next time the program runs, however - and all subsequent executions - the chmod will set the file's permissions so that the owner, group, and world (all users) can read the file and write to it:

(result)

-rw-rw-rw- 1 username 13 Nov 24 17:58 secretFile.out

Perhaps the programmer tried to do this because a different process uses different permissions that might prevent the file from being updated.

Example 4

This program creates and reads from an admin file to determine privilege information.

If the admin file doesn't exist, the program will create one. In order to create the file, the program must have write privileges to write to the file. After the file is created, the permissions need to be changed to read only.

(bad code)

Example Language: Go

const adminFile = "/etc/admin-users"
func createAdminFileIfNotExists() error {

file, err := os.Create(adminFile)
if err != nil {

return err

}
return nil

}

func changeModeOfAdminFile() error {

fileMode := os.FileMode(0440)
if err := os.Chmod(adminFile, fileMode); err != nil {

return err

}
return nil

}

os.Create will create a file with 0666 permissions before umask if the specified file does not exist. A typical umask of 0022 would result in the file having 0644 permissions. That is, the file would have world-writable and world-readable permissions.

In this scenario, it is advised to use the more customizable method of os.OpenFile with the os.O_WRONLY and os.O_CREATE flags specifying 0640 permissions to create the admin file.

This is because on a typical system where the umask is 0022, the perm 0640 applied in os.OpenFile will result in a file of 0620 where only the owner and group can write.

Example 5

The following command recursively sets world-readable permissions for a directory and all of its children:

(bad code)

Example Language: Shell

chmod -R ugo+r DIRNAME

If this command is run from a program, the person calling the program might not expect that all the files under the directory will be world-readable. If the directory is expected to contain private data, this could become a security problem.

Example 6

The following Azure command updates the settings for a storage account:

(bad code)

Example Language: Shell

az storage account update --name <storage-account> --resource-group <resource-group> --allow-blob-public-access true

However, "Allow Blob Public Access" is set to true, meaning that anonymous/public users can access blobs.

The command could be modified to disable "Allow Blob Public Access" by setting it to false.

(good code)

Example Language: Shell

az storage account update --name <storage-account> --resource-group <resource-group> --allow-blob-public-access false

Example 7

The following Google Cloud Storage command gets the settings for a storage account named 'BUCKET_NAME':

(informative)

Example Language: Shell

gsutil iam get gs://BUCKET_NAME

Suppose the command returns the following result:

(bad code)

Example Language: JSON

{

"bindings":[{

"members":[

"projectEditor: PROJECT-ID",
"projectOwner: PROJECT-ID"

],
"role":"roles/storage.legacyBucketOwner"

},
{

"members":[

"allUsers",
"projectViewer: PROJECT-ID"
],
"role":"roles/storage.legacyBucketReader"

}

]

}

This result includes the "allUsers" or IAM role added as members, causing this policy configuration to allow public access to cloud storage resources. There would be a similar concern if "allAuthenticatedUsers" was present.

The command could be modified to remove "allUsers" and/or "allAuthenticatedUsers" as follows:

(good code)

Example Language: Shell

gsutil iam ch -d allUsers gs://BUCKET_NAME
gsutil iam ch -d allAuthenticatedUsers gs://BUCKET_NAME

Observed Examples

Reference	Description
CVE-2022-29527	Go application for cloud management creates a world-writable sudoers file that allows local attackers to inject sudo rules and escalate privileges to root by winning a race condition.
CVE-2009-3482	Anti-virus product sets insecure "Everyone: Full Control" permissions for files under the "Program Files" folder, allowing attackers to replace executables with Trojan horses.
CVE-2009-3897	Product creates directories with 0777 permissions at installation, allowing users to gain privileges and access a socket used for authentication.
CVE-2009-3489	Photo editor installs a service with an insecure security descriptor, allowing users to stop or start the service, or execute commands as SYSTEM.
CVE-2020-15708	socket created with insecure permissions
CVE-2009-3289	Library function copies a file to a new target and uses the source file's permissions for the target, which is incorrect when the source file is a symbolic link, which typically has 0777 permissions.
CVE-2009-0115	Device driver uses world-writable permissions for a socket file, allowing attackers to inject arbitrary commands.
CVE-2009-1073	LDAP server stores a cleartext password in a world-readable file.
CVE-2009-0141	Terminal emulator creates TTY devices with world-writable permissions, allowing an attacker to write to the terminals of other users.
CVE-2008-0662	VPN product stores user credentials in a registry key with "Everyone: Full Control" permissions, allowing attackers to steal the credentials.
CVE-2008-0322	Driver installs its device interface with "Everyone: Write" permissions.
CVE-2009-3939	Driver installs a file with world-writable permissions.
CVE-2009-3611	Product changes permissions to 0777 before deleting a backup; the permissions stay insecure for subsequent backups.
CVE-2007-6033	Product creates a share with "Everyone: Full Control" permissions, allowing arbitrary program execution.
CVE-2007-5544	Product uses "Everyone: Full Control" permissions for memory-mapped files (shared memory) in inter-process communication, allowing attackers to tamper with a session.
CVE-2005-4868	Database product uses read/write permissions for everyone for its shared memory, allowing theft of credentials.
CVE-2004-1714	Security product uses "Everyone: Full Control" permissions for its configuration files.
CVE-2001-0006	"Everyone: Full Control" permissions assigned to a mutex allows users to disable network connectivity.
CVE-2002-0969	Chain: database product contains buffer overflow that is only reachable through a .ini configuration file - which has "Everyone: Full Control" permissions.

Detection Methods

Automated Static Analysis

Automated static analysis may be effective in detecting permission problems for system resources such as files, directories, shared memory, device interfaces, etc. Automated techniques may be able to detect the use of library functions that modify permissions, then analyze function calls for arguments that contain potentially insecure values.

However, since the software's intended security policy might allow loose permissions for certain operations (such as publishing a file on a web server), automated static analysis may produce some false positives - i.e., warnings that do not have any security consequences or require any code changes.

When custom permissions models are used - such as defining who can read messages in a particular forum in a bulletin board system - these can be difficult to detect using automated static analysis. It may be possible to define custom signatures that identify any custom functions that implement the permission checks and assignments.

Automated Dynamic Analysis

Automated dynamic analysis may be effective in detecting permission problems for system resources such as files, directories, shared memory, device interfaces, etc.

However, since the software's intended security policy might allow loose permissions for certain operations (such as publishing a file on a web server), automated dynamic analysis may produce some false positives - i.e., warnings that do not have any security consequences or require any code changes.

When custom permissions models are used - such as defining who can read messages in a particular forum in a bulletin board system - these can be difficult to detect using automated dynamic analysis. It may be possible to define custom signatures that identify any custom functions that implement the permission checks and assignments.

Manual Analysis

Note: These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Manual Static Analysis

Manual static analysis may be effective in detecting the use of custom permissions models and functions. The code could then be examined to identifying usage of the related functions. Then the human analyst could evaluate permission assignments in the context of the intended security model of the software.

Manual Dynamic Analysis

Manual dynamic analysis may be effective in detecting the use of custom permissions models and functions. The program could then be executed with a focus on exercising code paths that are related to the custom permissions. Then the human analyst could evaluate permission assignments in the context of the intended security model of the software.

Fuzzing

Fuzzing is not effective in detecting this weakness.

Black Box

Attach the monitor to the process and watch for library functions or system calls on OS resources such as files, directories, and shared memory. Examine the arguments to these calls to infer which permissions are being used.

Note: Note that this technique is only useful for permissions issues related to system resources. It is not likely to detect application-level business rules that are related to permissions, such as if a user of a blog system marks a post as "private," but the blog system inadvertently marks it as "public."

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Inter-application Flow Analysis

Effectiveness: SOAR Partial

Manual Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Host-based Vulnerability Scanners - Examine configuration for flaws, verifying that audit mechanisms work, ensure host configuration meets certain predefined criteria

Web Application Scanner

Web Services Scanner

Database Scanners

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Host Application Interface Scanner

Cost effective for partial coverage:

Fuzz Tester

Framework-based Fuzzer

Automated Monitored Execution

Forced Path Execution

Effectiveness: High

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Manual Source Code Review (not inspections)

Cost effective for partial coverage:

Focused Manual Spotcheck - Focused manual analysis of source

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Automated Static Analysis

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Configuration Checker

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	743	CERT C Secure Coding Standard (2008) Chapter 10 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	753	2009 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	803	2010 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	815	OWASP Top Ten 2010 Category A6 - Security Misconfiguration
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	857	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 14 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	859	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 16 - Platform Security (SEC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	860	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 17 - Runtime Environment (ENV)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	866	2011 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	877	CERT C++ Secure Coding Section 09 - Input Output (FIO)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	946	SFP Secondary Cluster: Insecure Resource Permissions
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1147	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 13. Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1149	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 15. Platform Security (SEC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1150	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 16. Runtime Environment (ENV)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1200	Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1337	Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1350	Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1396	Comprehensive Categorization: Access Control

Vulnerability Mapping Notes

Usage: ALLOWED-WITH-REVIEW

(this CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review)

Reason: Frequent Misuse

Rationale:

While the name itself indicates an assignment of permissions for resources, this is often misused for vulnerabilities in which "permissions" are not checked, which is an "authorization" weakness (CWE-285 or descendants) within CWE's model [REF-1287].

Comments:

Closely analyze the specific mistake that is allowing the resource to be exposed, and perform a CWE mapping for that mistake.

Notes

Maintenance

The relationships between privileges, permissions, and actors (e.g. users and groups) need further refinement within the Research view. One complication is that these concepts apply to two different pillars, related to control of resources (CWE-664) and protection mechanism failures (CWE-693).

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
The CERT Oracle Secure Coding Standard for Java (2011)	FIO03-J	Create files with appropriate access permission
The CERT Oracle Secure Coding Standard for Java (2011)	SEC01-J	Do not allow tainted variables in privileged blocks
The CERT Oracle Secure Coding Standard for Java (2011)	ENV03-J	Do not grant dangerous combinations of permissions
CERT C Secure Coding	FIO06-C	Create files with appropriate access permissions

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-1	Accessing Functionality Not Properly Constrained by ACLs
CAPEC-122	Privilege Abuse
CAPEC-127	Directory Indexing
CAPEC-17	Using Malicious Files
CAPEC-180	Exploiting Incorrectly Configured Access Control Security Levels
CAPEC-206	Signing Malicious Code
CAPEC-234	Hijacking a privileged process
CAPEC-60	Reusing Session IDs (aka Session Replay)
CAPEC-61	Session Fixation
CAPEC-62	Cross Site Request Forgery
CAPEC-642	Replace Binaries

References

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 9, "File Permissions." Page 495. 1st Edition. Addison Wesley. 2006.

[REF-207] John Viega and Gary McGraw. "Building Secure Software: How to Avoid Security Problems the Right Way". Chapter 8, "Access Control." Page 194. 1st Edition. Addison-Wesley. 2002.

[REF-594] Jason Lam. "Top 25 Series - Rank 21 - Incorrect Permission Assignment for Critical Response". SANS Software Security Institute. 2010-03-24. <http://software-security.sans.org/blog/2010/03/24/top-25-series-rank-21-incorrect-permission-assignment-for-critical-response>.

[REF-199] NIST. "United States Government Configuration Baseline (USGCB)". <https://csrc.nist.gov/Projects/United-States-Government-Configuration-Baseline>. URL validated: 2023-03-28.

[REF-1287] MITRE. "Supplemental Details - 2022 CWE Top 25". Details of Problematic Mappings. 2022-06-28. <https://cwe.mitre.org/top25/archive/2022/2022_cwe_top25_supplemental.html#problematicMappingDetails>.

[REF-1307] Center for Internet Security. "CIS Microsoft Azure Foundations Benchmark version 1.5.0". Section 3.7. 2022-08-16. <https://www.cisecurity.org/benchmark/azure>. URL validated: 2023-01-19.

[REF-1327] Center for Internet Security. "CIS Google Cloud Computing Platform Benchmark version 1.3.0". Section 5.1. 2022-03-31. <https://www.cisecurity.org/benchmark/google_cloud_computing_platform>. URL validated: 2023-04-24.

Content History

Submissions
Submission Date	Submitter	Organization
2008-09-08 (CWE 1.0, 2008-09-09)	CWE Content Team	MITRE
2008-09-08 (CWE 1.0, 2008-09-09)	new weakness-focused entry for Research view.
Modifications
Modification Date	Modifier	Organization
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Description, Likelihood_of_Exploit, Name, Potential_Mitigations, Relationships
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations, Related_Attack_Patterns
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Name
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Detection_Factors, Modes_of_Introduction, Observed_Examples, Potential_Mitigations, References
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Relationships
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Potential_Mitigations, Related_Attack_Patterns
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, Detection_Factors, Potential_Mitigations, References, Relationships
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Potential_Mitigations, Relationships
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Potential_Mitigations
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Demonstrative_Examples, Description, Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated References, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2013-07-17	CWE Content Team	MITRE
2013-07-17	updated References
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Detection_Factors, Relationships
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Related_Attack_Patterns, Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Likelihood_of_Exploit, Modes_of_Introduction, References, Relationships, Taxonomy_Mappings
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Maintenance_Notes, Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Description, Detection_Factors, Modes_of_Introduction, Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Observed_Examples, Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Demonstrative_Examples, Observed_Examples, References
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Applicable_Platforms, Description, References
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Demonstrative_Examples, Description, Potential_Mitigations, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
Previous Entry Names
Change Date	Previous Entry Name
2009-01-12	Insecure Permission Assignment for Resource

2009-05-27	Insecure Permission Assignment for Critical Resource

Weakness ID: 311

View customized information:

Description

The product does not encrypt sensitive or critical information before storage or transmission.

Extended Description

The lack of proper data encryption passes up the guarantees of confidentiality, integrity, and accountability that properly implemented encryption conveys.

Common Consequences

Scope	Impact	Likelihood
Confidentiality	Technical Impact: Read Application Data If the application does not use a secure channel, such as SSL, to exchange sensitive information, it is possible for an attacker with access to the network traffic to sniff packets from the connection and uncover the data. This attack is not technically difficult, but does require physical access to some portion of the network over which the sensitive data travels. This access is usually somewhere near where the user is connected to the network (such as a colleague on the company network) but can be anywhere along the path from the user to the end server.
Confidentiality Integrity	Technical Impact: Modify Application Data Omitting the use of encryption in any program which transfers data over a network of any kind should be considered on par with delivering the data sent to each user on the local networks of both the sender and receiver. Worse, this omission allows for the injection of data into a stream of communication between two parties -- with no means for the victims to separate valid data from invalid. In this day of widespread network attacks and password collection sniffers, it is an unnecessary risk to omit encryption from the design of any system which might benefit from it.

Potential Mitigations

Phase: Requirements

Clearly specify which data or resources are valuable enough that they should be protected by encryption. Require that any transmission or storage of this data/resource should use well-vetted encryption algorithms.

Phase: Architecture and Design

Ensure that encryption is properly integrated into the system design, including but not necessarily limited to:

Encryption that is needed to store or transmit private data of the users of the system

Encryption that is needed to protect the system itself from unauthorized disclosure or tampering

Identify the separate needs and contexts for encryption:

One-way (i.e., only the user or recipient needs to have the key). This can be achieved using public key cryptography, or other techniques in which the encrypting party (i.e., the product) does not need to have access to a private key.

Two-way (i.e., the encryption can be automatically performed on behalf of a user, but the key must be available so that the plaintext can be automatically recoverable by that user). This requires storage of the private key in a format that is recoverable only by the user (or perhaps by the operating system) in a way that cannot be recovered by others.

Using threat modeling or other techniques, assume that data can be compromised through a separate vulnerability or weakness, and determine where encryption will be most effective. Ensure that data that should be private is not being inadvertently exposed using weaknesses such as insecure permissions (CWE-732). [REF-7]

Phase: Architecture and Design

Strategy: Libraries or Frameworks

When there is a need to store or transmit sensitive data, use strong, up-to-date cryptographic algorithms to encrypt that data. Select a well-vetted algorithm that is currently considered to be strong by experts in the field, and use well-tested implementations. As with all cryptographic mechanisms, the source code should be available for analysis.

For example, US government systems require FIPS 140-2 certification.

Do not develop custom or private cryptographic algorithms. They will likely be exposed to attacks that are well-understood by cryptographers. Reverse engineering techniques are mature. If the algorithm can be compromised if attackers find out how it works, then it is especially weak.

Periodically ensure that the cryptography has not become obsolete. Some older algorithms, once thought to require a billion years of computing time, can now be broken in days or hours. This includes MD4, MD5, SHA1, DES, and other algorithms that were once regarded as strong. [REF-267]

Phase: Architecture and Design

Strategy: Separation of Privilege

Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.

Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Phases: Implementation; Architecture and Design

When using industry-approved techniques, use them correctly. Don't cut corners by skipping resource-intensive steps (CWE-325). These steps are often essential for preventing common attacks.

Phase: Implementation

Strategy: Attack Surface Reduction

Effectiveness: Defense in Depth

Note: This makes it easier to spot places in the code where data is being used that is unencrypted.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	693	Protection Mechanism Failure
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	312	Cleartext Storage of Sensitive Information
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	319	Cleartext Transmission of Sensitive Information
PeerOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	327	Use of a Broken or Risky Cryptographic Algorithm

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	312	Cleartext Storage of Sensitive Information
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	319	Cleartext Transmission of Sensitive Information

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1013	Encrypt Data

Modes Of Introduction

Phase	Note
Architecture and Design	OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Operation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

This code writes a user's login information to a cookie so the user does not have to login again later.

(bad code)

Example Language: PHP

function persistLogin($username, $password){

$data = array("username" => $username, "password"=> $password);
setcookie ("userdata", $data);

}

The code stores the user's username and password in plaintext in a cookie on the user's machine. This exposes the user's login information if their computer is compromised by an attacker. Even if the user's machine is not compromised, this weakness combined with cross-site scripting (CWE-79) could allow an attacker to remotely copy the cookie.

Also note this example code also exhibits Plaintext Storage in a Cookie (CWE-315).

Example 2

The following code attempts to establish a connection, read in a password, then store it to a buffer.

(bad code)

Example Language: C

server.sin_family = AF_INET; hp = gethostbyname(argv[1]);
if (hp==NULL) error("Unknown host");
memcpy( (char *)&server.sin_addr,(char *)hp->h_addr,hp->h_length);
if (argc < 3) port = 80;
else port = (unsigned short)atoi(argv[3]);
server.sin_port = htons(port);
if (connect(sock, (struct sockaddr *)&server, sizeof server) < 0) error("Connecting");
...
while ((n=read(sock,buffer,BUFSIZE-1))!=-1) {

write(dfd,password_buffer,n);
...

While successful, the program does not encrypt the data before writing it to a buffer, possibly exposing it to unauthorized actors.

Example 3

The following code attempts to establish a connection to a site to communicate sensitive information.

(bad code)

Example Language: Java

try {

}
catch (IOException e) {

//...

}

Though a connection is successfully made, the connection is unencrypted and it is possible that all sensitive data sent to or received from the server will be read by unintended actors.

Observed Examples

Reference	Description
CVE-2009-2272	password and username stored in cleartext in a cookie
CVE-2009-1466	password stored in cleartext in a file with insecure permissions
CVE-2009-0152	chat program disables SSL in some circumstances even when the user says to use SSL.
CVE-2009-1603	Chain: product uses an incorrect public exponent when generating an RSA key, which effectively disables the encryption
CVE-2009-0964	storage of unencrypted passwords in a database
CVE-2008-6157	storage of unencrypted passwords in a database
CVE-2008-6828	product stores a password in cleartext in memory
CVE-2008-1567	storage of a secret key in cleartext in a temporary file
CVE-2008-0174	SCADA product uses HTTP Basic Authentication, which is not encrypted
CVE-2007-5778	login credentials stored unencrypted in a registry key
CVE-2002-1949	Passwords transmitted in cleartext.
CVE-2008-4122	Chain: Use of HTTPS cookie without "secure" flag causes it to be transmitted across unencrypted HTTP.
CVE-2008-3289	Product sends password hash in cleartext in violation of intended policy.
CVE-2008-4390	Remote management feature sends sensitive information including passwords in cleartext.
CVE-2007-5626	Backup routine sends password in cleartext in email.
CVE-2004-1852	Product transmits Blowfish encryption key in cleartext.
CVE-2008-0374	Printer sends configuration information, including administrative password, in cleartext.
CVE-2007-4961	Chain: cleartext transmission of the MD5 hash of password enables attacks against a server that is susceptible to replay (CWE-294).
CVE-2007-4786	Product sends passwords in cleartext to a log server.
CVE-2005-3140	Product sends file with cleartext passwords in e-mail message intended for diagnostic purposes.

Detection Methods

Manual Analysis

The characterizaton of sensitive data often requires domain-specific understanding, so manual methods are useful. However, manual efforts might not achieve desired code coverage within limited time constraints. Black box methods may produce artifacts (e.g. stored data or unencrypted network transfer) that require manual evaluation.

Effectiveness: High

Automated Analysis

Automated measurement of the entropy of an input/output source may indicate the use or lack of encryption, but human analysis is still required to distinguish intentionally-unencrypted data (e.g. metadata) from sensitive data.

Manual Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Web Application Scanner

Web Services Scanner

Database Scanners

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Network Sniffer

Cost effective for partial coverage:

Fuzz Tester

Framework-based Fuzzer

Automated Monitored Execution

Man-in-the-middle attack tool

Effectiveness: High

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Focused Manual Spotcheck - Focused manual analysis of source

Manual Source Code Review (not inspections)

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Attack Modeling

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	719	OWASP Top Ten 2007 Category A8 - Insecure Cryptographic Storage
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	720	OWASP Top Ten 2007 Category A9 - Insecure Communications
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	729	OWASP Top Ten 2004 Category A8 - Insecure Storage
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	803	2010 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	816	OWASP Top Ten 2010 Category A7 - Insecure Cryptographic Storage
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	818	OWASP Top Ten 2010 Category A9 - Insufficient Transport Layer Protection
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	861	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	866	2011 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	930	OWASP Top Ten 2013 Category A2 - Broken Authentication and Session Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	934	OWASP Top Ten 2013 Category A6 - Sensitive Data Exposure
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	963	SFP Secondary Cluster: Exposed Data
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1029	OWASP Top Ten 2017 Category A3 - Sensitive Data Exposure
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1152	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 49. Miscellaneous (MSC)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1348	OWASP Top Ten 2021 Category A04:2021 - Insecure Design
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1366	ICS Communications: Frail Security in Protocols
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1402	Comprehensive Categorization: Encryption

Vulnerability Mapping Notes

Usage: DISCOURAGED

(this CWE ID should not be used to map to real-world vulnerabilities)

Reason: Abstraction

Rationale:

CWE-311 is high-level with more precise children available. It is a level-1 Class (i.e., a child of a Pillar).

Comments:

Consider children CWE-312: Cleartext Storage of Sensitive Information or CWE-319: Cleartext Transmission of Sensitive Information.

Notes

Relationship

There is an overlapping relationship between insecure storage of sensitive information (CWE-922) and missing encryption of sensitive information (CWE-311). Encryption is often used to prevent an attacker from reading the sensitive data. However, encryption does not prevent the attacker from erasing or overwriting the data.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
CLASP			Failure to encrypt data
OWASP Top Ten 2007	A8	CWE More Specific	Insecure Cryptographic Storage
OWASP Top Ten 2007	A9	CWE More Specific	Insecure Communications
OWASP Top Ten 2004	A8	CWE More Specific	Insecure Storage
WASC	4		Insufficient Transport Layer Protection
The CERT Oracle Secure Coding Standard for Java (2011)	MSC00-J		Use SSLSocket rather than Socket for secure data exchange
Software Fault Patterns	SFP23		Exposed Data
ISA/IEC 62443	Part 3-3		Req SR 4.1
ISA/IEC 62443	Part 3-3		Req SR 4.3
ISA/IEC 62443	Part 4-2		Req CR 4.1
ISA/IEC 62443	Part 4-2		Req CR 7.3
ISA/IEC 62443	Part 4-2		Req CR 1.5

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-157	Sniffing Attacks
CAPEC-158	Sniffing Network Traffic
CAPEC-204	Lifting Sensitive Data Embedded in Cache
CAPEC-31	Accessing/Intercepting/Modifying HTTP Cookies
CAPEC-37	Retrieve Embedded Sensitive Data
CAPEC-383	Harvesting Information via API Event Monitoring
CAPEC-384	Application API Message Manipulation via Man-in-the-Middle
CAPEC-385	Transaction or Event Tampering via Application API Manipulation
CAPEC-386	Application API Navigation Remapping
CAPEC-387	Navigation Remapping To Propagate Malicious Content
CAPEC-388	Application API Button Hijacking
CAPEC-477	Signature Spoofing by Mixing Signed and Unsigned Content
CAPEC-609	Cellular Traffic Intercept
CAPEC-65	Sniff Application Code

References

[REF-18] Secure Software, Inc.. "The CLASP Application Security Process". 2005. <https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf>.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 17: Failure to Protect Stored Data." Page 253. McGraw-Hill. 2010.

[REF-265] Frank Kim. "Top 25 Series - Rank 10 - Missing Encryption of Sensitive Data". SANS Software Security Institute. 2010-02-26. <https://www.sans.org/blog/top-25-series-rank-10-missing-encryption-of-sensitive-data/>. URL validated: 2023-04-07.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 2, "Common Vulnerabilities of Encryption", Page 43. 1st Edition. Addison Wesley. 2006.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	CLASP
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2023-11-14 (CWE 4.14, 2024-02-29)	participants in the CWE ICS/OT SIG 62443 Mapping Fall Workshop
2023-11-14 (CWE 4.14, 2024-02-29)	Contributed or reviewed taxonomy mappings for ISA/IEC 62443
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-08-15		Veracode
2008-08-15	Suggested OWASP Top Ten 2004 mapping
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Common_Consequences, Other_Notes
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Description, Detection_Factors, Likelihood_of_Exploit, Name, Observed_Examples, Potential_Mitigations, References, Related_Attack_Patterns, Relationships, Taxonomy_Mappings, Time_of_Introduction
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Related_Attack_Patterns
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, Potential_Mitigations, References
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Potential_Mitigations
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Demonstrative_Examples, Observed_Examples, Related_Attack_Patterns
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Demonstrative_Examples
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, Relationships
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, References, Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations, References
2013-07-17	CWE Content Team	MITRE
2013-07-17	updated Relationship_Notes
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Related_Attack_Patterns
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Detection_Factors, Relationships, Taxonomy_Mappings
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Related_Attack_Patterns
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Related_Attack_Patterns
2017-05-03	CWE Content Team	MITRE
2017-05-03	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Likelihood_of_Exploit, Modes_of_Introduction, Potential_Mitigations, References, Relationships
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References, Relationships
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Related_Attack_Patterns, Relationships, Type
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated References, Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Potential_Mitigations, Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-06-28	CWE Content Team	MITRE
2022-06-28	updated Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description, Potential_Mitigations
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Taxonomy_Mappings
Previous Entry Names
Change Date	Previous Entry Name
2008-04-11	Failure to Encrypt Data

2010-02-16	Failure to Encrypt Sensitive Data

Weakness ID: 807

View customized information:

Description

The product uses a protection mechanism that relies on the existence or values of an input, but the input can be modified by an untrusted actor in a way that bypasses the protection mechanism.

Extended Description

Developers may assume that inputs such as cookies, environment variables, and hidden form fields cannot be modified. However, an attacker could change these inputs using customized clients or other attacks. This change might not be detected. When security decisions such as authentication and authorization are made based on the values of these inputs, attackers can bypass the security of the software.

Without sufficient encryption, integrity checking, or other mechanism, any input that originates from an outsider cannot be trusted.

Common Consequences

Scope	Impact	Likelihood
Confidentiality Access Control Availability Other	Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity; Varies by Context Attackers can bypass the security decision to access whatever is being protected. The consequences will depend on the associated functionality, but they can range from granting additional privileges to untrusted users to bypassing important security checks. Ultimately, this weakness may lead to exposure or modification of sensitive data, system crash, or execution of arbitrary code.

Potential Mitigations

Phase: Architecture and Design

Strategy: Attack Surface Reduction

Store state information and sensitive data on the server side only.

Ensure that the system definitively and unambiguously keeps track of its own state and user state and has rules defined for legitimate state transitions. Do not allow any application user to affect state directly in any way other than through legitimate actions leading to state transitions.

If information must be stored on the client, do not do so without encryption and integrity checking, or otherwise having a mechanism on the server side to catch tampering. Use a message authentication code (MAC) algorithm, such as Hash Message Authentication Code (HMAC) [REF-529]. Apply this against the state or sensitive data that has to be exposed, which can guarantee the integrity of the data - i.e., that the data has not been modified. Ensure that a strong hash function is used (CWE-328).

Phase: Architecture and Design

Strategy: Libraries or Frameworks

Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

With a stateless protocol such as HTTP, use a framework that maintains the state for you.

Examples include ASP.NET View State [REF-756] and the OWASP ESAPI Session Management feature [REF-45].

Be careful of language features that provide state support, since these might be provided as a convenience to the programmer and may not be considering security.

Phase: Architecture and Design

Phases: Operation; Implementation

Strategy: Environment Hardening

Phases: Architecture and Design; Implementation

Strategy: Attack Surface Reduction

Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.

Identify all inputs that are used for security decisions and determine if you can modify the design so that you do not have to rely on submitted inputs at all. For example, you may be able to keep critical information about the user's session on the server side instead of recording it within external data.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	693	Protection Mechanism Failure
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	302	Authentication Bypass by Assumed-Immutable Data
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	350	Reliance on Reverse DNS Resolution for a Security-Critical Action
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	784	Reliance on Cookies without Validation and Integrity Checking in a Security Decision

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1006	Bad Coding Practices

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1012	Cross Cutting

Modes Of Introduction

Phase	Note
Architecture and Design	COMMISSION: This weakness refers to an incorrect design related to an architectural security tactic.
Implementation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

The following code excerpt reads a value from a browser cookie to determine the role of the user.

(bad code)

Example Language: Java

Cookie[] cookies = request.getCookies();
for (int i =0; i< cookies.length; i++) {

Cookie c = cookies[i];
if (c.getName().equals("role")) {

userRole = c.getValue();

}

Example 2

The following code could be for a medical records application. It performs authentication by checking if a cookie has been set.

(bad code)

Example Language: PHP

$auth = $_COOKIES['authenticated'];
if (! $auth) {

if (AuthenticateUser($_POST['user'], $_POST['password']) == "success") {

// save the cookie to send out in future responses
setcookie("authenticated", "1", time()+60*60*2);

}
else {

ShowLoginScreen();
die("\n");

}

}
DisplayMedicalHistory($_POST['patient_ID']);

The programmer expects that the AuthenticateUser() check will always be applied, and the "authenticated" cookie will only be set when authentication succeeds. The programmer even diligently specifies a 2-hour expiration for the cookie.

However, the attacker can set the "authenticated" cookie to a non-zero value such as 1. As a result, the $auth variable is 1, and the AuthenticateUser() check is not even performed. The attacker has bypassed the authentication.

Example 3

In the following example, an authentication flag is read from a browser cookie, thus allowing for external control of user state data.

(bad code)

Example Language: Java

Cookie[] cookies = request.getCookies();
for (int i =0; i< cookies.length; i++) {

Cookie c = cookies[i];
if (c.getName().equals("authenticated") && Boolean.TRUE.equals(c.getValue())) {

authenticated = true;

}

Example 4

The following code samples use a DNS lookup in order to decide whether or not an inbound request is from a trusted host. If an attacker can poison the DNS cache, they can gain trusted status.

(bad code)

Example Language: C

struct hostent *hp;struct in_addr myaddr;
char* tHost = "trustme.example.com";
myaddr.s_addr=inet_addr(ip_addr_string);

hp = gethostbyaddr((char *) &myaddr, sizeof(struct in_addr), AF_INET);
if (hp && !strncmp(hp->h_name, tHost, sizeof(tHost))) {

trusted = true;

} else {

trusted = false;

}

(bad code)

Example Language: Java

String ip = request.getRemoteAddr();
InetAddress addr = InetAddress.getByName(ip);
if (addr.getCanonicalHostName().endsWith("trustme.com")) {

trusted = true;

}

(bad code)

Example Language: C#

IPAddress hostIPAddress = IPAddress.Parse(RemoteIpAddress);
IPHostEntry hostInfo = Dns.GetHostByAddress(hostIPAddress);
if (hostInfo.HostName.EndsWith("trustme.com")) {

trusted = true;

}

IP addresses are more reliable than DNS names, but they can also be spoofed. Attackers can easily forge the source IP address of the packets they send, but response packets will return to the forged IP address. To see the response packets, the attacker has to sniff the traffic between the victim machine and the forged IP address. In order to accomplish the required sniffing, attackers typically attempt to locate themselves on the same subnet as the victim machine. Attackers may be able to circumvent this requirement by using source routing, but source routing is disabled across much of the Internet today. In summary, IP address verification can be a useful part of an authentication scheme, but it should not be the single factor required for authentication.

Observed Examples

Reference	Description
CVE-2009-1549	Attacker can bypass authentication by setting a cookie to a specific value.
CVE-2009-1619	Attacker can bypass authentication and gain admin privileges by setting an "admin" cookie to 1.
CVE-2009-0864	Content management system allows admin privileges by setting a "login" cookie to "OK."
CVE-2008-5784	e-dating application allows admin privileges by setting the admin cookie to 1.
CVE-2008-6291	Web-based email list manager allows attackers to gain admin privileges by setting a login cookie to "admin."

Detection Methods

Manual Static Analysis

Effectiveness: High

Note: The effectiveness and speed of manual analysis will be reduced if the there is not a centralized security mechanism, and the security logic is widely distributed throughout the software.

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Bytecode Weakness Analysis - including disassembler + source code weakness analysis

Binary Weakness Analysis - including disassembler + source code weakness analysis

Effectiveness: SOAR Partial

Manual Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Web Application Scanner

Web Services Scanner

Database Scanners

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Fuzz Tester

Framework-based Fuzzer

Monitored Virtual Environment - run potentially malicious code in sandbox / wrapper / virtual machine, see if it does anything suspicious

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Manual Source Code Review (not inspections)

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Source code Weakness Analyzer

Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Attack Modeling

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	803	2010 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	859	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 16 - Platform Security (SEC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	866	2011 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	878	CERT C++ Secure Coding Section 10 - Environment (ENV)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1348	OWASP Top Ten 2021 Category A04:2021 - Insecure Design
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1365	ICS Communications: Unreliability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1373	ICS Engineering (Construction/Deployment): Trust Model Problems
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1413	Comprehensive Categorization: Protection Mechanism Failure

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
The CERT Oracle Secure Coding Standard for Java (2011)	SEC09-J		Do not base security checks on untrusted sources

References

[REF-754] Frank Kim. "Top 25 Series - Rank 6 - Reliance on Untrusted Inputs in a Security Decision". SANS Software Security Institute. 2010-03-05. <https://www.sans.org/blog/top-25-series-rank-6-reliance-on-untrusted-inputs-in-a-security-decision/>. URL validated: 2023-04-07.

[REF-529] "HMAC". Wikipedia. 2011-08-18. <https://en.wikipedia.org/wiki/HMAC>. URL validated: 2023-04-07.

[REF-756] Scott Mitchell. "Understanding ASP.NET View State". Microsoft. 2004-05-15. <https://learn.microsoft.com/en-us/previous-versions/dotnet/articles/ms972976(v=msdn.10)?redirectedfrom=MSDN>. URL validated: 2023-04-07.

[REF-45] OWASP. "OWASP Enterprise Security API (ESAPI) Project". <http://www.owasp.org/index.php/ESAPI>.

Content History

Submissions
Submission Date	Submitter	Organization
2010-01-18 (CWE 1.8, 2010-02-16)	CWE Content Team	MITRE
2010-01-18 (CWE 1.8, 2010-02-16)
Modifications
Modification Date	Modifier	Organization
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, Potential_Mitigations, References
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Potential_Mitigations
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Common_Consequences, Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, References, Relationships
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Potential_Mitigations
2013-07-17	CWE Content Team	MITRE
2013-07-17	updated Relationships
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Potential_Mitigations
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Detection_Factors
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Likelihood_of_Exploit, Modes_of_Introduction, References, Relationships, Taxonomy_Mappings
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Taxonomy_Mappings
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-04-28	CWE Content Team	MITRE
2022-04-28	updated Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Potential_Mitigations, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships

Weakness ID: 252

View customized information:

Description

The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.

Extended Description

Two common programmer assumptions are "this function call can never fail" and "it doesn't matter if this function call fails". If an attacker can force the function to fail or otherwise return a value that is not expected, then the subsequent program logic could lead to a vulnerability, because the product is not in a state that the programmer assumes. For example, if the program calls a function to drop privileges but does not check the return code to ensure that privileges were successfully dropped, then the program will continue to operate with the higher privileges.

Common Consequences

Scope	Impact	Likelihood
Availability Integrity	Technical Impact: Unexpected State; DoS: Crash, Exit, or Restart An unexpected return value could place the system in a state that could lead to a crash or other unintended behaviors.

Potential Mitigations

Phase: Implementation

Check the results of all functions that return a value and verify that the value is expected.

Effectiveness: High

Note: Checking the return value of the function will typically be sufficient, however beware of race conditions (CWE-362) in a concurrent environment.

Phase: Implementation

Ensure that you account for all possible return values from the function.

Phase: Implementation

When designing a function, make sure you return a value or throw an exception in case of an error.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	754	Improper Check for Unusual or Exceptional Conditions
ParentOf	Chain - a Compound Element that is a sequence of two or more separate weaknesses that can be closely linked together within software. One weakness, X, can directly create the conditions that are necessary to cause another weakness, Y, to enter a vulnerable condition. When this happens, CWE refers to X as "primary" to Y, and Y is "resultant" from X. Chains can involve more than two weaknesses, and in some cases, they might have a tree-like structure.	690	Unchecked Return Value to NULL Pointer Dereference
PeerOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	273	Improper Check for Dropped Privileges
CanPrecede	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	476	NULL Pointer Dereference

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	389	Error Conditions, Return Values, Status Codes

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	754	Improper Check for Unusual or Exceptional Conditions

Background Details

Many functions will return some value about the success of their actions. This will alert the program whether or not to handle any errors caused by that function.

Modes Of Introduction

Phase	Note
Implementation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

Low

Demonstrative Examples

Example 1

Consider the following code segment:

(bad code)

Example Language: C

char buf[10], cp_buf[10];
fgets(buf, 10, stdin);
strcpy(cp_buf, buf);

Example 2

In the following example, it is possible to request that memcpy move a much larger segment of memory than assumed:

(bad code)

Example Language: C

int returnChunkSize(void *) {

/* if chunk info is valid, return the size of usable memory,

* else, return -1 to indicate an error

*/
...

}
int main() {

...
memcpy(destBuf, srcBuf, (returnChunkSize(destBuf)-1));
...

}

If returnChunkSize() happens to encounter an error it will return -1. Notice that the return value is not checked before the memcpy operation (CWE-252), so -1 can be passed as the size argument to memcpy() (CWE-805). Because memcpy() assumes that the value is unsigned, it will be interpreted as MAXINT-1 (CWE-195), and therefore will copy far more memory than is likely available to the destination buffer (CWE-787, CWE-788).

Example 3

The following code does not check to see if memory allocation succeeded before attempting to use the pointer returned by malloc().

(bad code)

Example Language: C

buf = (char*) malloc(req_size);
strncpy(buf, xfer, req_size);

The traditional defense of this coding error is: "If my program runs out of memory, it will fail. It doesn't matter whether I handle the error or allow the program to die with a segmentation fault when it tries to dereference the null pointer." This argument ignores three important considerations:

Depending upon the type and size of the application, it may be possible to free memory that is being used elsewhere so that execution can continue.
It is impossible for the program to perform a graceful exit if required. If the program is performing an atomic operation, it can leave the system in an inconsistent state.
The programmer has lost the opportunity to record diagnostic information. Did the call to malloc() fail because req_size was too large or because there were too many requests being handled at the same time? Or was it caused by a memory leak that has built up over time? Without handling the error, there is no way to know.

Example 4

The following examples read a file into a byte array.

(bad code)

Example Language: C#

char[] byteArray = new char[1024];
for (IEnumerator i=users.GetEnumerator(); i.MoveNext() ;i.Current()) {

String userName = (String) i.Current();
String pFileName = PFILE_ROOT + "/" + userName;
StreamReader sr = new StreamReader(pFileName);
sr.Read(byteArray,0,1024);//the file is always 1k bytes
sr.Close();
processPFile(userName, byteArray);

}

(bad code)

Example Language: Java

FileInputStream fis;
byte[] byteArray = new byte[1024];
for (Iterator i=users.iterator(); i.hasNext();) {

String userName = (String) i.next();
String pFileName = PFILE_ROOT + "/" + userName;
FileInputStream fis = new FileInputStream(pFileName);
fis.read(byteArray); // the file is always 1k bytes
fis.close();
processPFile(userName, byteArray);

The code loops through a set of users, reading a private data file for each user. The programmer assumes that the files are always 1 kilobyte in size and therefore ignores the return value from Read(). If an attacker can create a smaller file, the program will recycle the remainder of the data from the previous user and treat it as though it belongs to the attacker.

Example 5

The following code does not check to see if the string returned by getParameter() is null before calling the member function compareTo(), potentially causing a NULL dereference.

(bad code)

Example Language: Java

String itemName = request.getParameter(ITEM_NAME);
if (itemName.compareTo(IMPORTANT_ITEM) == 0) {

...

}
...

The following code does not check to see if the string returned by the Item property is null before calling the member function Equals(), potentially causing a NULL dereference.

(bad code)

Example Language: Java

String itemName = request.Item(ITEM_NAME);
if (itemName.Equals(IMPORTANT_ITEM)) {

...

}
...

The traditional defense of this coding error is: "I know the requested value will always exist because.... If it does not exist, the program cannot perform the desired behavior so it doesn't matter whether I handle the error or allow the program to die dereferencing a null value." But attackers are skilled at finding unexpected paths through programs, particularly when exceptions are involved.

Example 6

The following code shows a system property that is set to null and later dereferenced by a programmer who mistakenly assumes it will always be defined.

(bad code)

Example Language: Java

System.clearProperty("os.name");
...
String os = System.getProperty("os.name");
if (os.equalsIgnoreCase("Windows 95")) System.out.println("Not supported");

Example 7

The following VB.NET code does not check to make sure that it has read 50 bytes from myfile.txt. This can cause DoDangerousOperation() to operate on an unexpected value.

(bad code)

Example Language: C#

Dim MyFile As New FileStream("myfile.txt", FileMode.Open, FileAccess.Read, FileShare.Read)
Dim MyArray(50) As Byte
MyFile.Read(MyArray, 0, 50)
DoDangerousOperation(MyArray(20))

In .NET, it is not uncommon for programmers to misunderstand Read() and related methods that are part of many System.IO classes. The stream and reader classes do not consider it to be unusual or exceptional if only a small amount of data becomes available. These classes simply add the small amount of data to the return buffer, and set the return value to the number of bytes or characters read. There is no guarantee that the amount of data returned is equal to the amount of data requested.

Example 8

It is not uncommon for Java programmers to misunderstand read() and related methods that are part of many java.io classes. Most errors and unusual events in Java result in an exception being thrown. But the stream and reader classes do not consider it unusual or exceptional if only a small amount of data becomes available. These classes simply add the small amount of data to the return buffer, and set the return value to the number of bytes or characters read. There is no guarantee that the amount of data returned is equal to the amount of data requested. This behavior makes it important for programmers to examine the return value from read() and other IO methods to ensure that they receive the amount of data they expect.

Example 9

This example takes an IP address from a user, verifies that it is well formed and then looks up the hostname and copies it into a buffer.

(bad code)

Example Language: C

void host_lookup(char *user_supplied_addr){

struct hostent *hp;
in_addr_t *addr;
char hostname[64];
in_addr_t inet_addr(const char *cp);

/*routine that ensures user_supplied_addr is in the right format for conversion */

validate_addr_form(user_supplied_addr);
addr = inet_addr(user_supplied_addr);
hp = gethostbyaddr( addr, sizeof(struct in_addr), AF_INET);
strcpy(hostname, hp->h_name);

}

If an attacker provides an address that appears to be well-formed, but the address does not resolve to a hostname, then the call to gethostbyaddr() will return NULL. Since the code does not check the return value from gethostbyaddr (CWE-252), a NULL pointer dereference (CWE-476) would then occur in the call to strcpy().

Note that this code is also vulnerable to a buffer overflow (CWE-119).

Example 10

The following function attempts to acquire a lock in order to perform operations on a shared resource.

(bad code)

Example Language: C

void f(pthread_mutex_t *mutex) {

pthread_mutex_lock(mutex);

/* access shared resource */

pthread_mutex_unlock(mutex);

}

(good code)

Example Language: C

int f(pthread_mutex_t *mutex) {

int result;

result = pthread_mutex_lock(mutex);
if (0 != result)

return result;

/* access shared resource */

return pthread_mutex_unlock(mutex);

}

Observed Examples

Reference	Description
CVE-2020-17533	Chain: unchecked return value (CWE-252) of some functions for policy enforcement leads to authorization bypass (CWE-862)
CVE-2020-6078	Chain: The return value of a function returning a pointer is not checked for success (CWE-252) resulting in the later use of an uninitialized variable (CWE-456) and a null pointer dereference (CWE-476)
CVE-2019-15900	Chain: sscanf() call is used to check if a username and group exists, but the return value of sscanf() call is not checked (CWE-252), causing an uninitialized variable to be checked (CWE-457), returning success to allow authorization bypass for executing a privileged (CWE-863).
CVE-2007-3798	Unchecked return value leads to resultant integer overflow and code execution.
CVE-2006-4447	Program does not check return value when invoking functions to drop privileges, which could leave users with higher privileges than expected by forcing those functions to fail.
CVE-2006-2916	Program does not check return value when invoking functions to drop privileges, which could leave users with higher privileges than expected by forcing those functions to fail.
CVE-2008-5183	chain: unchecked return value can lead to NULL dereference
CVE-2010-0211	chain: unchecked return value (CWE-252) leads to free of invalid, uninitialized pointer (CWE-824).
CVE-2017-6964	Linux-based device mapper encryption program does not check the return value of setuid and setgid allowing attackers to execute code with unintended privileges.
CVE-2002-1372	Chain: Return values of file/socket operations are not checked (CWE-252), allowing resultant consumption of file descriptors (CWE-772).

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)

Detection Methods

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	227	7PK - API Abuse
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	728	OWASP Top Ten 2004 Category A7 - Improper Error Handling
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	742	CERT C Secure Coding Standard (2008) Chapter 9 - Memory Management (MEM)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	847	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 4 - Expressions (EXP)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	876	CERT C++ Secure Coding Section 08 - Memory Management (MEM)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	962	SFP Secondary Cluster: Unchecked Status Condition
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1129	CISQ Quality Measures (2016) - Reliability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1131	CISQ Quality Measures (2016) - Security
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1136	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 02. Expressions (EXP)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1167	SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1171	SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1181	SEI CERT Perl Coding Standard - Guidelines 03. Expressions (EXP)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1306	CISQ Quality Measures - Reliability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1405	Comprehensive Categorization: Improper Check or Handling of Exceptional Conditions

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
7 Pernicious Kingdoms			Unchecked Return Value
CLASP			Ignored function return value
OWASP Top Ten 2004	A7	CWE More Specific	Improper Error Handling
CERT C Secure Coding	ERR33-C	Imprecise	Detect and handle standard library errors
CERT C Secure Coding	POS54-C	Imprecise	Detect and handle POSIX library errors
The CERT Oracle Secure Coding Standard for Java (2011)	EXP00-J		Do not ignore values returned by methods
SEI CERT Perl Coding Standard	EXP32-PL	Exact	Do not ignore function return values
Software Fault Patterns	SFP4		Unchecked Status Condition
OMG ASCSM	ASCSM-CWE-252-resource
OMG ASCRM	ASCRM-CWE-252-data
OMG ASCRM	ASCRM-CWE-252-resource

References

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 7, "Program Building Blocks" Page 341. 1st Edition. Addison Wesley. 2006.

[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 20, "Checking Returns" Page 624. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 11: Failure to Handle Errors Correctly." Page 183. McGraw-Hill. 2010.

[REF-961] Object Management Group (OMG). "Automated Source Code Reliability Measure (ASCRM)". ASCRM-CWE-252-data. 2016-01. <http://www.omg.org/spec/ASCRM/1.0/>.

[REF-961] Object Management Group (OMG). "Automated Source Code Reliability Measure (ASCRM)". ASCRM-CWE-252-resource. 2016-01. <http://www.omg.org/spec/ASCRM/1.0/>.

[REF-962] Object Management Group (OMG). "Automated Source Code Security Measure (ASCSM)". ASCSM-CWE-252-resource. 2016-01. <http://www.omg.org/spec/ASCSM/1.0/>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	7 Pernicious Kingdoms
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2010-04-30	Martin Sebor	Cisco Systems, Inc.
2010-04-30	Provided Demonstrative Example and suggested CERT reference
Modifications
Modification Date	Modifier	Organization
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Relationships, Taxonomy_Mappings
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Background_Details, Demonstrative_Examples, Description, Observed_Examples, Other_Notes, Potential_Mitigations
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Relationships
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Demonstrative_Examples
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Demonstrative_Examples
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Common_Consequences, Demonstrative_Examples, References
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Demonstrative_Examples, Potential_Mitigations, References
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Demonstrative_Examples
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Demonstrative_Examples, References
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Observed_Examples
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Demonstrative_Examples
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Demonstrative_Examples, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Common_Consequences
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Common_Consequences, References, Relationships
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Demonstrative_Examples, Potential_Mitigations
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Demonstrative_Examples, Relationships, Taxonomy_Mappings
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, References, Relationships, Taxonomy_Mappings
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated References, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated References
2020-06-25	CWE Content Team	MITRE
2020-06-25	updated Observed_Examples
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Demonstrative_Examples, Observed_Examples, Relationships, Weakness_Ordinalities
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Observed_Examples
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
2023-10-26	CWE Content Team	MITRE
2023-10-26	updated Observed_Examples

Weakness ID: 400

View customized information:

Description

Extended Description

Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system.

There are at least three distinct scenarios which can commonly lead to resource exhaustion:

Lack of throttling for the number of allocated resources
Losing all references to a resource before reaching the shutdown stage
Not closing/returning a resource after processing

Resource exhaustion problems are often result due to an incorrect implementation of the following situations:

Error conditions and other exceptional circumstances.
Confusion over which part of the program is responsible for releasing the resource.

Alternate Terms

Resource Exhaustion

Common Consequences

Scope	Impact	Likelihood
Availability	Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other) The most common result of resource exhaustion is denial of service. The product may slow down, crash due to unhandled errors, or lock out legitimate users.
Access Control Other	Technical Impact: Bypass Protection Mechanism; Other In some cases it may be possible to force the product to "fail open" in the event of resource exhaustion. The state of the product -- and possibly the security functionality - may then be compromised.

Potential Mitigations

Phase: Architecture and Design

Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.

Phase: Architecture and Design

Mitigation of resource exhaustion attacks requires that the target system either:

recognizes the attack and denies that user further access for a given amount of time, or

uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.

The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

Phase: Architecture and Design

Ensure that protocols have specific limits of scale placed on them.

Phase: Implementation

Ensure that all failures in resource allocation place the system into a safe posture.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	664	Improper Control of a Resource Through its Lifetime
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	405	Asymmetric Resource Consumption (Amplification)
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	770	Allocation of Resources Without Limits or Throttling
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	771	Missing Reference to Active Allocated Resource
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	779	Logging of Excessive Data
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	920	Improper Restriction of Power Consumption
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1235	Incorrect Use of Autoboxing and Unboxing for Performance Critical Operations
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1246	Improper Write Handling in Limited-write Non-Volatile Memories
CanFollow	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	410	Insufficient Resource Pool

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	770	Allocation of Resources Without Limits or Throttling
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	920	Improper Restriction of Power Consumption

Modes Of Introduction

Phase	Note
Operation
Architecture and Design
Implementation

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

The following example demonstrates the weakness.

(bad code)

Example Language: Java

class Worker implements Executor {

...
public void execute(Runnable r) {

try {

...

}
catch (InterruptedException ie) {

// postpone response
Thread.currentThread().interrupt();

}

}

public Worker(Channel ch, int nworkers) {

...

}

protected void activate() {

Runnable loop = new Runnable() {

public void run() {

try {

for (;;) {

Runnable r = ...;
r.run();

}

}
catch (InterruptedException ie) {

...

}

};
new Thread(loop).start();

}

There are no limits to runnables. Potentially an attacker could cause resource problems very quickly.

Example 2

This code allocates a socket and forks each time it receives a new connection.

(bad code)

Example Language: C

sock=socket(AF_INET, SOCK_STREAM, 0);
while (1) {

newsock=accept(sock, ...);
printf("A connection has been accepted\n");
pid = fork();

}

Example 3

(bad code)

Example Language: C

int writeDataFromSocketToFile(char *host, int port)
{

char filename[FILENAME_SIZE];
char buffer[BUFFER_SIZE];
int socket = openSocketConnection(host, port);

if (socket < 0) {

printf("Unable to open socket connection");
return(FAIL);

}
if (getNextMessage(socket, filename, FILENAME_SIZE) > 0) {

if (openFileToWrite(filename) > 0) {

while (getNextMessage(socket, buffer, BUFFER_SIZE) > 0){

if (!(writeToFile(buffer) > 0))

break;

}

}
closeFile();

}
closeSocket(socket);

}

Example 4

(bad code)

Example Language: C

/* process message accepts a two-dimensional character array of the form [length][body] containing the message to be processed */
int processMessage(char **message)
{

char *body;

int length = getMessageLength(message[0]);

if (length > 0) {

body = &message[1][0];
processMessageBody(body);
return(SUCCESS);

}
else {

printf("Unable to process message; invalid message length");
return(FAIL);

}

(good code)

Example Language: C

unsigned int length = getMessageLength(message[0]);
if ((length > 0) && (length < MAX_LENGTH)) {...}

Example 5

(bad code)

Example Language: Java

public void acceptConnections() {

try {

ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
int counter = 0;
boolean hasConnections = true;
while (hasConnections) {

Socket client = serverSocket.accept();
Thread t = new Thread(new ClientSocketThread(client));
t.setName(client.getInetAddress().getHostName() + ":" + counter++);
t.start();

}
serverSocket.close();

} catch (IOException ex) {...}

}

(good code)

Example Language: Java

public static final int SERVER_PORT = 4444;
public static final int MAX_CONNECTIONS = 10;
...

public void acceptConnections() {

try {

ServerSocket serverSocket = new ServerSocket(SERVER_PORT);
int counter = 0;
boolean hasConnections = true;
while (hasConnections) {

}
serverSocket.close();

} catch (IOException ex) {...}

}

Example 6

In the following example, the serve function receives an http request and an http response writer. It reads the entire request body.

(bad code)

Example Language: Go

func serve(w http.ResponseWriter, r *http.Request) {

var body []byte
if r.Body != nil {

if data, err := io.ReadAll(r.Body); err == nil {

body = data

}

Because ReadAll is defined to read from src until EOF, it does not treat an EOF from Read as an error to be reported. This example creates a situation where the length of the body supplied can be very large and will consume excessive memory, exhausting system resources. This can be avoided by ensuring the body does not exceed a predetermined length of bytes.

MaxBytesReader prevents clients from accidentally or maliciously sending a large request and wasting server resources. If possible, the code could be changed to tell ResponseWriter to close the connection after the limit has been reached.

(good code)

Example Language: Go

func serve(w http.ResponseWriter, r *http.Request) {

var body []byte
const MaxRespBodyLength = 1e6
if r.Body != nil {

r.Body = http.MaxBytesReader(w, r.Body, MaxRespBodyLength)
if data, err := io.ReadAll(r.Body); err == nil {

body = data

}

Observed Examples

Reference	Description
CVE-2022-21668	Chain: Python library does not limit the resources used to process images that specify a very large number of bands (CWE-1284), leading to excessive memory consumption (CWE-789) or an integer overflow (CWE-190).
CVE-2020-7218	Go-based workload orchestrator does not limit resource usage with unauthenticated connections, allowing a DoS by flooding the service
CVE-2020-3566	Resource exhaustion in distributed OS because of "insufficient" IGMP queue management, as exploited in the wild per CISA KEV.
CVE-2009-2874	Product allows attackers to cause a crash via a large number of connections.
CVE-2009-1928	Malformed request triggers uncontrolled recursion, leading to stack exhaustion.
CVE-2009-2858	Chain: memory leak (CWE-404) leads to resource exhaustion.
CVE-2009-2726	Driver does not use a maximum width when invoking sscanf style functions, causing stack consumption.
CVE-2009-2540	Large integer value for a length property in an object causes a large amount of memory allocation.
CVE-2009-2299	Web application firewall consumes excessive memory when an HTTP request contains a large Content-Length value but no POST data.
CVE-2009-2054	Product allows exhaustion of file descriptors when processing a large number of TCP packets.
CVE-2008-5180	Communication product allows memory consumption with a large number of SIP requests, which cause many sessions to be created.
CVE-2008-2121	TCP implementation allows attackers to consume CPU and prevent new connections using a TCP SYN flood attack.
CVE-2008-2122	Port scan triggers CPU consumption with processes that attempt to read data from closed sockets.
CVE-2008-1700	Product allows attackers to cause a denial of service via a large number of directives, each of which opens a separate window.
CVE-2007-4103	Product allows resource exhaustion via a large number of calls that do not complete a 3-way handshake.
CVE-2006-1173	Mail server does not properly handle deeply nested multipart MIME messages, leading to stack exhaustion.
CVE-2007-0897	Chain: anti-virus product encounters a malformed file but returns from a function without closing a file descriptor (CWE-775) leading to file descriptor consumption (CWE-400) and failed scans.

Detection Methods

Automated Static Analysis

Automated static analysis typically has limited utility in recognizing resource exhaustion problems, except for program-independent system resources such as files, sockets, and processes. For system resources, automated static analysis may be able to detect circumstances in which resources are not released after they have expired. Automated analysis of configuration files may be able to detect settings that do not specify a maximum value.

Effectiveness: Limited

Automated Dynamic Analysis

Certain automated dynamic analysis techniques may be effective in spotting resource exhaustion problems, especially with resources such as processes, memory, and connections. The technique may involve generating a large number of requests to the product within a short time frame.

Effectiveness: Moderate

Fuzzing

While fuzzing is typically geared toward finding low-level implementation bugs, it can inadvertently find resource exhaustion problems. This can occur when the fuzzer generates a large number of test cases but does not restart the targeted product in between test cases. If an individual test case produces a crash, but it does not do so reliably, then an inability to handle resource exhaustion may be the cause.

Effectiveness: Opportunistic

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	730	OWASP Top Ten 2004 Category A9 - Denial of Service
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	858	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	861	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	985	SFP Secondary Cluster: Unrestricted Consumption
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1148	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 14. Serialization (SER)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1152	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 49. Miscellaneous (MSC)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1200	Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1350	Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1387	Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1416	Comprehensive Categorization: Resource Lifecycle Management

Vulnerability Mapping Notes

Usage: DISCOURAGED

(this CWE ID should not be used to map to real-world vulnerabilities)

Reason: Frequent Misuse

Rationale:

CWE-400 is intended for incorrect behaviors in which the product is expected to track and restrict how many resources it consumes, but CWE-400 is often misused because it is conflated with the "technical impact" of vulnerabilities in which resource consumption occurs. It is sometimes used for low-information vulnerability reports. It is a level-1 Class (i.e., a child of a Pillar).

Comments:

Closely analyze the specific mistake that is causing resource consumption, and perform a CWE mapping for that mistake. Consider children/descendants such as CWE-770: Allocation of Resources Without Limits or Throttling, CWE-771: Missing Reference to Active Allocated Resource, CWE-410: Insufficient Resource Pool, CWE-772: Missing Release of Resource after Effective Lifetime, CWE-834: Excessive Iteration, CWE-405: Asymmetric Resource Consumption (Amplification), and others.

Notes

Theoretical

Vulnerability theory is largely about how behaviors and resources interact. "Resource exhaustion" can be regarded as either a consequence or an attack, depending on the perspective. This entry is an attempt to reflect the underlying weaknesses that enable these attacks (or consequences) to take place.

Other

Database queries that take a long time to process are good DoS targets. An attacker would have to write a few lines of Perl code to generate enough traffic to exceed the site's ability to keep up. This would effectively prevent authorized users from using the site at all. Resources can be exploited simply by ensuring that the target machine must do much more work and consume more resources in order to service a request than the attacker must do to initiate a request.

A prime example of this can be found in old switches that were vulnerable to "macof" attacks (so named for a tool developed by Dugsong). These attacks flooded a switch with random IP and MAC address combinations, therefore exhausting the switch's cache, which held the information of which port corresponded to which MAC addresses. Once this cache was exhausted, the switch would fail in an insecure way and would begin to act simply as a hub, broadcasting all traffic on all ports and allowing for basic sniffing attacks.

Maintenance

"Resource consumption" could be interpreted as a consequence instead of an insecure behavior, so this entry is being considered for modification. It appears to be referenced too frequently when more precise mappings are available. Some of its children, such as CWE-771, might be better considered as a chain.

Maintenance

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
CLASP			Resource exhaustion (file descriptor, disk space, sockets, ...)
OWASP Top Ten 2004	A9	CWE More Specific	Denial of Service
WASC	10		Denial of Service
WASC	41		XML Attribute Blowup
The CERT Oracle Secure Coding Standard for Java (2011)	SER12-J		Avoid memory and resource leaks during serialization
The CERT Oracle Secure Coding Standard for Java (2011)	MSC05-J		Do not exhaust heap space
Software Fault Patterns	SFP13		Unrestricted Consumption
ISA/IEC 62443	Part 3-3		Req SR 7.1
ISA/IEC 62443	Part 3-3		Req SR 7.2
ISA/IEC 62443	Part 4-1		Req SI-1
ISA/IEC 62443	Part 4-1		Req SVV-3
ISA/IEC 62443	Part 4-2		Req CR 7.1
ISA/IEC 62443	Part 4-2		Req CR 7.2

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-147	XML Ping of the Death
CAPEC-227	Sustained Client Engagement
CAPEC-492	Regular Expression Exponential Blowup

References

[REF-18] Secure Software, Inc.. "The CLASP Application Security Process". 2005. <https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf>.

[REF-387] D.J. Bernstein. "Resource exhaustion". <http://cr.yp.to/docs/resources.html>.

[REF-388] Pascal Meunier. "Resource exhaustion". Secure Programming Educational Material. 2004. <http://homes.cerias.purdue.edu/~pmeunier/secprog/sanitized/class1/6.resource%20exhaustion.ppt>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	CLASP
2006-07-19 (CWE Draft 3, 2006-07-19)
Contributions
Contribution Date	Contributor	Organization
2023-01-24 (CWE 4.10, 2023-01-31)	"Mapping CWE to 62443" Sub-Working Group	CWE-CAPEC ICS/OT SIG
2023-01-24 (CWE 4.10, 2023-01-31)	Suggested mappings to ISA/IEC 62443.
2023-04-25	"Mapping CWE to 62443" Sub-Working Group	CWE-CAPEC ICS/OT SIG
2023-04-25	Suggested mappings to ISA/IEC 62443.
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-08-15		Veracode
2008-08-15	Suggested OWASP Top Ten 2004 mapping
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Description, Name, Relationships
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Description
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Name, Relationships
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Description, Relationships
2009-10-29	CWE Content Team	MITRE
2009-10-29	updated Relationships
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Common_Consequences, Demonstrative_Examples, Detection_Factors, Likelihood_of_Exploit, Observed_Examples, Other_Notes, Potential_Mitigations, References
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Detection_Factors, Potential_Mitigations, References, Taxonomy_Mappings
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Related_Attack_Patterns
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Description
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Demonstrative_Examples
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2013-07-17	CWE Content Team	MITRE
2013-07-17	updated Relationships
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Related_Attack_Patterns, Relationships
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, Demonstrative_Examples, Likelihood_of_Exploit, Potential_Mitigations, References, Relationships
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References, Type
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Alternate_Terms, Description, Name, Relationships, Taxonomy_Mappings, Theoretical_Notes
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Related_Attack_Patterns, Relationships
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Description, Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Description, References, Related_Attack_Patterns, Relationships
2020-06-25	CWE Content Team	MITRE
2020-06-25	updated Description, Maintenance_Notes
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2022-04-28	CWE Content Team	MITRE
2022-04-28	updated Related_Attack_Patterns
2022-06-28	CWE Content Team	MITRE
2022-06-28	updated Observed_Examples, Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Observed_Examples, Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Common_Consequences, Description, Detection_Factors, Maintenance_Notes, Related_Attack_Patterns, Taxonomy_Mappings
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Demonstrative_Examples, Relationships, Taxonomy_Mappings
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
Previous Entry Names
Change Date	Previous Entry Name
2008-10-14	Resource Exhaustion

2009-05-27	Uncontrolled Resource Consumption (aka 'Resource Exhaustion')

2019-01-03	Uncontrolled Resource Consumption ('Resource Exhaustion')

Weakness ID: 134

View customized information:

Description

The product uses a function that accepts a format string as an argument, but the format string originates from an external source.

Extended Description

When an attacker can modify an externally-controlled format string, this can lead to buffer overflows, denial of service, or data representation problems.

It should be noted that in some circumstances, such as internationalization, the set of format strings is externally controlled by design. If the source of these format strings is trusted (e.g. only contained in library files that are only modifiable by the system administrator), then the external control might not itself pose a vulnerability.

Common Consequences

Scope	Impact	Likelihood
Confidentiality	Technical Impact: Read Memory Format string problems allow for information disclosure which can severely simplify exploitation of the program.
Integrity Confidentiality Availability	Technical Impact: Modify Memory; Execute Unauthorized Code or Commands Format string problems can result in the execution of arbitrary code.

Potential Mitigations

Phase: Requirements

Choose a language that is not subject to this flaw.

Phase: Implementation

Ensure that all format string functions are passed a static string which cannot be controlled by the user, and that the proper number of arguments are always sent to that function as well. If at all possible, use functions that do not support the %n operator in format strings. [REF-116] [REF-117]

Phase: Build and Compilation

Run compilers and linkers with high warning levels, since they may detect incorrect usage.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	668	Exposure of Resource to Wrong Sphere
CanPrecede	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	123	Write-what-where Condition

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	133	String Errors

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	668	Exposure of Resource to Wrong Sphere

Relevant to the view "Seven Pernicious Kingdoms" (CWE-700)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	20	Improper Input Validation

Modes Of Introduction

Phase	Note
Implementation	The programmer rarely intends for a format string to be externally-controlled at all. This weakness is frequently introduced in code that constructs log messages, where a constant format string is omitted.
Implementation	In cases such as localization and internationalization, the language-specific message repositories could be an avenue for exploitation, but the format string issue would be resultant, since attacker control of those repositories would also allow modification of message length, format, and content.

Applicable Platforms

Languages

C (Often Prevalent)

C++ (Often Prevalent)

Perl (Rarely Prevalent)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

The following program prints a string provided as an argument.

(bad code)

Example Language: C

#include <stdio.h>

void printWrapper(char *string) {

printf(string);

}

int main(int argc, char **argv) {

char buf[5012];
memcpy(buf, argv[1], 5012);
printWrapper(argv[1]);
return (0);

}

The example is exploitable, because of the call to printf() in the printWrapper() function. Note: The stack buffer was added to make exploitation more simple.

Example 2

The following code copies a command line argument into a buffer using snprintf().

(bad code)

Example Language: C

int main(int argc, char **argv){

char buf[128];
...
snprintf(buf,128,argv[1]);

}

This code allows an attacker to view the contents of the stack and write to the stack using a command line argument containing a sequence of formatting directives. The attacker can read from the stack by providing more formatting directives, such as %x, than the function takes as arguments to be formatted. (In this example, the function takes no arguments to be formatted.) By using the %n formatting directive, the attacker can write to the stack, causing snprintf() to write the number of bytes output thus far to the specified argument (rather than reading a value from the argument, which is the intended behavior). A sophisticated version of this attack will use four staggered writes to completely control the value of a pointer on the stack.

Example 3

Certain implementations make more advanced attacks even easier by providing format directives that control the location in memory to read from or write to. An example of these directives is shown in the following code, written for glibc:

(bad code)

Example Language: C

printf("%d %d %1$d %1$d\n", 5, 9);

This code produces the following output: 5 9 5 5 It is also possible to use half-writes (%hn) to accurately control arbitrary DWORDS in memory, which greatly reduces the complexity needed to execute an attack that would otherwise require four staggered writes, such as the one mentioned in the first example.

Observed Examples

Reference	Description
CVE-2002-1825	format string in Perl program
CVE-2001-0717	format string in bad call to syslog function
CVE-2002-0573	format string in bad call to syslog function
CVE-2002-1788	format strings in NNTP server responses
CVE-2006-2480	Format string vulnerability exploited by triggering errors or warnings, as demonstrated via format string specifiers in a .bmp filename.
CVE-2007-2027	Chain: untrusted search path enabling resultant format string by loading malicious internationalization messages

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)

Detection Methods

Automated Static Analysis

This weakness can often be detected using automated static analysis tools. Many modern tools use data flow analysis or constraint-based techniques to minimize the number of false positives.

Black Box

Since format strings often occur in rarely-occurring erroneous conditions (e.g. for error message logging), they can be difficult to detect using black box methods. It is highly likely that many latent issues exist in executables that do not have associated source code (or equivalent source.

Effectiveness: Limited

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Bytecode Weakness Analysis - including disassembler + source code weakness analysis

Binary Weakness Analysis - including disassembler + source code weakness analysis

Cost effective for partial coverage:

Binary / Bytecode simple extractor - strings, ELF readers, etc.

Effectiveness: High

Manual Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Web Application Scanner

Web Services Scanner

Database Scanners

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Fuzz Tester

Framework-based Fuzzer

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Manual Source Code Review (not inspections)

Cost effective for partial coverage:

Focused Manual Spotcheck - Focused manual analysis of source

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Source code Weakness Analyzer

Context-configured Source Code Weakness Analyzer

Cost effective for partial coverage:

Warning Flags

Effectiveness: High

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Formal Methods / Correct-By-Construction

Cost effective for partial coverage:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Effectiveness: High

Functional Areas

Logging
Error Handling
String Processing

Affected Resources

Memory

Memberships

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	635	Weaknesses Originally Used by NVD from 2008 to 2016
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	726	OWASP Top Ten 2004 Category A5 - Buffer Overflows
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	743	CERT C Secure Coding Standard (2008) Chapter 10 - Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	808	2010 Top 25 - Weaknesses On the Cusp
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	845	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 2 - Input Validation and Data Sanitization (IDS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	865	2011 Top 25 - Risky Resource Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	877	CERT C++ Secure Coding Section 09 - Input Output (FIO)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	990	SFP Secondary Cluster: Tainted Input to Command
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1131	CISQ Quality Measures (2016) - Security
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1134	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 00. Input Validation and Data Sanitization (IDS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1163	SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1179	SEI CERT Perl Coding Standard - Guidelines 01. Input Validation and Data Sanitization (IDS)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1399	Comprehensive Categorization: Memory Safety

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Applicable Platform

This weakness is possible in any programming language that support format strings.

Research Gap

Format string issues are under-studied for languages other than C. Memory or disk consumption, control flow or variable alteration, and data corruption may result from format string exploitation in applications written in other languages such as Perl, PHP, Python, etc.

Other

While Format String vulnerabilities typically fall under the Buffer Overflow category, technically they are not overflowed buffers. The Format String vulnerability is fairly new (circa 1999) and stems from the fact that there is no realistic way for a function that takes a variable number of arguments to determine just how many arguments were passed in. The most common functions that take a variable number of arguments, including C-runtime functions, are the printf() family of calls. The Format String problem appears in a number of ways. A *printf() call without a format specifier is dangerous and can be exploited. For example, printf(input); is exploitable, while printf(y, input); is not exploitable in that context. The result of the first call, used incorrectly, allows for an attacker to be able to peek at stack memory since the input string will be used as the format specifier. The attacker can stuff the input string with format specifiers and begin reading stack values, since the remaining parameters will be pulled from the stack. Worst case, this improper use may give away enough control to allow an arbitrary value (or values in the case of an exploit program) to be written into the memory of the running program.

Frequently targeted entities are file names, process names, identifiers.

Format string problems are a classic C/C++ issue that are now rare due to the ease of discovery. One main reason format string vulnerabilities can be exploited is due to the %n operator. The %n operator will write the number of characters, which have been printed by the format string therefore far, to the memory pointed to by its argument. Through skilled creation of a format string, a malicious user may use values on the stack to create a write-what-where condition. Once this is achieved, they can execute arbitrary code. Other operators can be used as well; for example, a %9999s operator could also trigger a buffer overflow, or when used in file-formatting functions like fprintf, it can generate a much larger output than intended.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
PLOVER			Format string vulnerability
7 Pernicious Kingdoms			Format String
CLASP			Format string problem
CERT C Secure Coding	FIO30-C	Exact	Exclude user input from format strings
CERT C Secure Coding	FIO47-C	CWE More Specific	Use valid format strings
OWASP Top Ten 2004	A1	CWE More Specific	Unvalidated Input
WASC	6		Format String
The CERT Oracle Secure Coding Standard for Java (2011)	IDS06-J		Exclude user input from format strings
SEI CERT Perl Coding Standard	IDS30-PL	Exact	Exclude user input from format strings
Software Fault Patterns	SFP24		Tainted input to command
OMG ASCSM	ASCSM-CWE-134

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-135	Format String Injection
CAPEC-67	String Format Overflow in syslog()

References

[REF-116] Steve Christey. "Format String Vulnerabilities in Perl Programs". <https://seclists.org/fulldisclosure/2005/Dec/91>. URL validated: 2023-04-07.

[REF-117] Hal Burch and Robert C. Seacord. "Programming Language Format String Vulnerabilities". <https://drdobbs.com/security/programming-language-format-string-vulne/197002914>. URL validated: 2023-04-07.

[REF-118] Tim Newsham. "Format String Attacks". Guardent. 2000-09-09. <http://www.thenewsh.com/~newsham/format-string-attacks.pdf>.

[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 5, "Format String Bugs" Page 147. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 6: Format String Problems." Page 109. McGraw-Hill. 2010.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 8, "C Format Strings", Page 422. 1st Edition. Addison Wesley. 2006.

[REF-962] Object Management Group (OMG). "Automated Source Code Security Measure (ASCSM)". ASCSM-CWE-134. 2016-01. <http://www.omg.org/spec/ASCSM/1.0/>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	PLOVER
2006-07-19 (CWE Draft 3, 2006-07-19)
Modifications
Modification Date	Modifier	Organization
2008-08-01		KDM Analytics
2008-08-01	added/updated white box definitions
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Applicable_Platforms, Common_Consequences, Detection_Factors, Modes_of_Introduction, Relationships, Other_Notes, Research_Gaps, Taxonomy_Mappings, Weakness_Ordinalities
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Relationships, Taxonomy_Mappings
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Relationships
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Demonstrative_Examples
2009-07-17	KDM Analytics
2009-07-17	Improved the White_Box_Definition
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated White_Box_Definitions
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Detection_Factors, References, Relationships, Taxonomy_Mappings
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Modes_of_Introduction, Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Observed_Examples, References, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Demonstrative_Examples, Detection_Factors, Relationships, Taxonomy_Mappings
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Description, Modes_of_Introduction, Name, Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Applicable_Platforms, Causal_Nature, Functional_Areas, Likelihood_of_Exploit, Other_Notes, References, Relationships, Taxonomy_Mappings, White_Box_Definitions
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated References, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Detection_Factors, Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Common_Consequences, Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Potential_Mitigations, Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2015-12-07	Uncontrolled Format String

Weakness ID: 798

View customized information:

Description

The product contains hard-coded credentials, such as a password or cryptographic key.

Extended Description

There are two main variations:

Inbound: the product contains an authentication mechanism that checks the input credentials against a hard-coded set of credentials. In this variant, a default administration account is created, and a simple password is hard-coded into the product and associated with that account. This hard-coded password is the same for each installation of the product, and it usually cannot be changed or disabled by system administrators without manually modifying the program, or otherwise patching the product. It can also be difficult for the administrator to detect.
Outbound: the product connects to another system or component, and it contains hard-coded credentials for connecting to that component. This variant applies to front-end systems that authenticate with a back-end service. The back-end service may require a fixed password that can be easily discovered. The programmer may simply hard-code those back-end credentials into the front-end product.

Common Consequences

Scope	Impact	Likelihood
Access Control	Technical Impact: Bypass Protection Mechanism If hard-coded passwords are used, it is almost certain that malicious users will gain access to the account in question. Any user of the product that hard-codes passwords may be able to extract the password. Client-side systems with hard-coded passwords pose even more of a threat, since the extraction of a password from a binary is usually very simple.
Integrity Confidentiality Availability Access Control Other	Technical Impact: Read Application Data; Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands; Other This weakness can lead to the exposure of resources or functionality to unintended actors, possibly providing attackers with sensitive information or even execute arbitrary code. If the password is ever discovered or published (a common occurrence on the Internet), then anybody with knowledge of this password can access the product. Finally, since all installations of the product will have the same password, even across different organizations, this enables massive attacks such as worms to take place.

Potential Mitigations

Phase: Architecture and Design

For outbound authentication: store passwords, keys, and other credentials outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible [REF-7].

In Windows environments, the Encrypted File System (EFS) may provide some protection.

Phase: Architecture and Design

For inbound authentication: Rather than hard-code a default username and password, key, or other authentication credentials for first time logins, utilize a "first login" mode that requires the user to enter a unique strong password or key.

Phase: Architecture and Design

If the product must contain hard-coded credentials or they cannot be removed, perform access control checks and limit which entities can access the feature that requires the hard-coded credentials. For example, a feature might only be enabled through the system console instead of through a network connection.

Phase: Architecture and Design

For inbound authentication using passwords: apply strong one-way hashes to passwords and store those hashes in a configuration file or database with appropriate access control. That way, theft of the file/database still requires the attacker to try to crack the password. When handling an incoming password during authentication, take the hash of the password and compare it to the saved hash.

Use randomly assigned salts for each separate hash that is generated. This increases the amount of computation that an attacker needs to conduct a brute-force attack, possibly limiting the effectiveness of the rainbow table method.

Phase: Architecture and Design

For front-end to back-end connections: Three solutions are possible, although none are complete.

The first suggestion involves the use of generated passwords or keys that are changed automatically and must be entered at given time intervals by a system administrator. These passwords will be held in memory and only be valid for the time intervals.

Next, the passwords or keys should be limited at the back end to only performing actions valid for the front end, as opposed to having full access.

Finally, the messages sent should be tagged and checksummed with time sensitive values so as to prevent replay-style attacks.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	344	Use of Invariant Value in Dynamically Changing Context
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	671	Lack of Administrator Control over Security
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	1391	Use of Weak Credentials
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	259	Use of Hard-coded Password
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	321	Use of Hard-coded Cryptographic Key
PeerOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	257	Storing Passwords in a Recoverable Format

Relevant to the view "Software Development" (CWE-699)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	255	Credentials Management Errors
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	320	Key Management Errors

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	287	Improper Authentication

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1010	Authenticate Actors

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	259	Use of Hard-coded Password
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	321	Use of Hard-coded Cryptographic Key

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	259	Use of Hard-coded Password
ParentOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	321	Use of Hard-coded Cryptographic Key

Modes Of Introduction

Phase	Note
Architecture and Design	REALIZATION: This weakness is caused during implementation of an architectural security tactic.

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: Mobile (Undetermined Prevalence)

Class: ICS/OT (Often Prevalent)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

The following code uses a hard-coded password to connect to a database:

(bad code)

Example Language: Java

...
DriverManager.getConnection(url, "scott", "tiger");
...

This is an example of an external hard-coded password on the client-side of a connection. This code will run successfully, but anyone who has access to it will have access to the password. Once the program has shipped, there is no going back from the database user "scott" with a password of "tiger" unless the program is patched. A devious employee with access to this information can use it to break into the system. Even worse, if attackers have access to the bytecode for application, they can use the javap -c command to access the disassembled code, which will contain the values of the passwords used. The result of this operation might look something like the following for the example above:

(attack code)

javap -c ConnMngr.class

22: ldc #36; //String jdbc:mysql://ixne.com/rxsql
24: ldc #38; //String scott
26: ldc #17; //String tiger

Example 2

The following code is an example of an internal hard-coded password in the back-end:

(bad code)

Example Language: C

int VerifyAdmin(char *password) {

if (strcmp(password, "Mew!")) {

printf("Incorrect Password!\n");
return(0)

}
printf("Entering Diagnostic Mode...\n");
return(1);

}

(bad code)

Example Language: Java

int VerifyAdmin(String password) {

if (!password.equals("Mew!")) {

return(0)

}
//Diagnostic Mode
return(1);

}

Every instance of this program can be placed into diagnostic mode with the same password. Even worse is the fact that if this program is distributed as a binary-only distribution, it is very difficult to change that password or disable this "functionality."

Example 3

The following code examples attempt to verify a password using a hard-coded cryptographic key.

(bad code)

Example Language: C

int VerifyAdmin(char *password) {

if (strcmp(password,"68af404b513073584c4b6f22b6c63e6b")) {

printf("Incorrect Password!\n");
return(0);

}
printf("Entering Diagnostic Mode...\n");
return(1);

}

(bad code)

Example Language: Java

public boolean VerifyAdmin(String password) {

if (password.equals("68af404b513073584c4b6f22b6c63e6b")) {

System.out.println("Entering Diagnostic Mode...");
return true;

}
System.out.println("Incorrect Password!");
return false;

(bad code)

Example Language: C#

int VerifyAdmin(String password) {

if (password.Equals("68af404b513073584c4b6f22b6c63e6b")) {

Console.WriteLine("Entering Diagnostic Mode...");
return(1);

}
Console.WriteLine("Incorrect Password!");
return(0);

}

The cryptographic key is within a hard-coded string value that is compared to the password. It is likely that an attacker will be able to read the key and compromise the system.

Example 4

The following examples show a portion of properties and configuration files for Java and ASP.NET applications. The files include username and password information but they are stored in cleartext.

This Java example shows a properties file with a cleartext username / password pair.

(bad code)

Example Language: Java

# Java Web App ResourceBundle properties file
...
webapp.ldap.username=secretUsername
webapp.ldap.password=secretPassword
...

The following example shows a portion of a configuration file for an ASP.Net application. This configuration file includes username and password information for a connection to a database but the pair is stored in cleartext.

(bad code)

Example Language: ASP.NET

...
<connectionStrings>

</connectionStrings>
...

Username and password information should not be included in a configuration file or a properties file in cleartext as this will allow anyone who can read the file access to the resource. If possible, encrypt this information.

Example 5

Multiple vendors used hard-coded credentials in their OT products.

Observed Examples

Reference	Description
CVE-2022-29953	Condition Monitor firmware has a maintenance interface with hard-coded credentials
CVE-2022-29960	Engineering Workstation uses hard-coded cryptographic keys that could allow for unathorized filesystem access and privilege escalation
CVE-2022-29964	Distributed Control System (DCS) has hard-coded passwords for local shell access
CVE-2022-30997	Programmable Logic Controller (PLC) has a maintenance service that uses undocumented, hard-coded credentials
CVE-2022-30314	Firmware for a Safety Instrumented System (SIS) has hard-coded credentials for access to boot configuration
CVE-2022-30271	Remote Terminal Unit (RTU) uses a hard-coded SSH private key that is likely to be used in typical deployments
CVE-2021-37555	Telnet service for IoT feeder for dogs and cats has hard-coded password [REF-1288]
CVE-2021-35033	Firmware for a WiFi router uses a hard-coded password for a BusyBox shell, allowing bypass of authentication through the UART port
CVE-2012-3503	Installation script has a hard-coded secret token value, allowing attackers to bypass authentication
CVE-2010-2772	SCADA system uses a hard-coded password to protect back-end database containing authorization information, exploited by Stuxnet worm
CVE-2010-2073	FTP server library uses hard-coded usernames and passwords for three default accounts
CVE-2010-1573	Chain: Router firmware uses hard-coded username and password for access to debug functionality, which can be used to execute arbitrary code
CVE-2008-2369	Server uses hard-coded authentication key
CVE-2008-0961	Backup product uses hard-coded username and password, allowing attackers to bypass authentication via the RPC interface
CVE-2008-1160	Security appliance uses hard-coded password allowing attackers to gain root access
CVE-2006-7142	Drive encryption product stores hard-coded cryptographic keys for encrypted configuration files in executable programs
CVE-2005-3716	VoIP product uses hard-coded public credentials that cannot be changed, which allows attackers to obtain sensitive information
CVE-2005-3803	VoIP product uses hard coded public and private SNMP community strings that cannot be changed, which allows remote attackers to obtain sensitive information
CVE-2005-0496	Backup product contains hard-coded credentials that effectively serve as a back door, which allows remote attackers to access the file system

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)

Detection Methods

Black Box

Credential storage in configuration files is findable using black box methods, but the use of hard-coded credentials for an incoming authentication routine typically involves an account that is not visible outside of the code.

Effectiveness: Moderate

Automated Static Analysis

Automated white box techniques have been published for detecting hard-coded credentials for incoming authentication, but there is some expert disagreement regarding their effectiveness and applicability to a broad range of methods.

Manual Static Analysis

This weakness may be detectable using manual code analysis. Unless authentication is decentralized and applied throughout the product, there can be sufficient time for the analyst to find incoming authentication routines and examine the program logic looking for usage of hard-coded credentials. Configuration files could also be analyzed.

Note: These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Manual Dynamic Analysis

For hard-coded credentials in incoming authentication: use monitoring tools that examine the product's process as it interacts with the operating system and the network. This technique is useful in cases when source code is unavailable, if the product was not developed by you, or if you want to verify that the build phase did not introduce any new weaknesses. Examples include debuggers that directly attach to the running process; system-call tracing utilities such as truss (Solaris) and strace (Linux); system activity monitors such as FileMon, RegMon, Process Monitor, and other Sysinternals utilities (Windows); and sniffers and protocol analyzers that monitor network traffic.

Attach the monitor to the process and perform a login. Using call trees or similar artifacts from the output, examine the associated behaviors and see if any of them appear to be comparing the input to a fixed string or value.

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Bytecode Weakness Analysis - including disassembler + source code weakness analysis

Binary Weakness Analysis - including disassembler + source code weakness analysis

Effectiveness: SOAR Partial

Manual Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: High

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Network Sniffer

Forced Path Execution

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Focused Manual Spotcheck - Focused manual analysis of source

Manual Source Code Review (not inspections)

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Source code Weakness Analyzer

Context-configured Source Code Weakness Analyzer

Effectiveness: High

Automated Static Analysis

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Configuration Checker

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Formal Methods / Correct-By-Construction

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	254	7PK - Security Features
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	724	OWASP Top Ten 2004 Category A3 - Broken Authentication and Session Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	753	2009 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	803	2010 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	812	OWASP Top Ten 2010 Category A3 - Broken Authentication and Session Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	861	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	866	2011 Top 25 - Porous Defenses
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	884	CWE Cross-section
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1131	CISQ Quality Measures (2016) - Security
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1152	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 49. Miscellaneous (MSC)
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1200	Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1308	CISQ Quality Measures - Security
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1337	Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1340	CISQ Data Protection Measures
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1350	Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1353	OWASP Top Ten 2021 Category A07:2021 - Identification and Authentication Failures
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1387	Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1396	Comprehensive Categorization: Access Control
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1425	Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Maintenance

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
The CERT Oracle Secure Coding Standard for Java (2011)	MSC03-J	Never hard code sensitive information
OMG ASCSM	ASCSM-CWE-798
ISA/IEC 62443	Part 3-3	Req SR 1.5
ISA/IEC 62443	Part 4-2	Req CR 1.5

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-191	Read Sensitive Constants Within an Executable
CAPEC-70	Try Common or Default Usernames and Passwords

References

[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 8, "Key Management Issues" Page 272. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.

[REF-729] Johannes Ullrich. "Top 25 Series - Rank 11 - Hardcoded Credentials". SANS Software Security Institute. 2010-03-10. <https://www.sans.org/blog/top-25-series-rank-11-hardcoded-credentials/>. URL validated: 2023-04-07.

[REF-172] Chris Wysopal. "Mobile App Top 10 List". 2010-12-13. <https://www.veracode.com/blog/2010/12/mobile-app-top-10-list>. URL validated: 2023-04-07.

[REF-962] Object Management Group (OMG). "Automated Source Code Security Measure (ASCSM)". ASCSM-CWE-798. 2016-01. <http://www.omg.org/spec/ASCSM/1.0/>.

[REF-1288] Julia Lokrantz. "Ethical hacking of a Smart Automatic Feed Dispenser". 2021-06-07. <http://kth.diva-portal.org/smash/get/diva2:1561552/FULLTEXT01.pdf>.

[REF-1304] ICS-CERT. "ICS Alert (ICS-ALERT-13-164-01): Medical Devices Hard-Coded Passwords". 2013-06-13. <https://www.cisa.gov/news-events/ics-alerts/ics-alert-13-164-01>. URL validated: 2023-04-07.

Content History

Submissions
Submission Date	Submitter	Organization
2010-01-15 (CWE 1.8, 2010-02-16)	CWE Content Team	MITRE
2010-01-15 (CWE 1.8, 2010-02-16)	More abstract entry for hard-coded password and hard-coded cryptographic key.
Contributions
Contribution Date	Contributor	Organization
2023-01-24 (CWE 4.10, 2023-01-31)	"Mapping CWE to 62443" Sub-Working Group	CWE-CAPEC ICS/OT SIG
2023-01-24 (CWE 4.10, 2023-01-31)	Suggested mappings to ISA/IEC 62443.
2024-02-29 (CWE 4.15, 2024-07-16)	Abhi Balakrishnan
2024-02-29 (CWE 4.15, 2024-07-16)	Provided diagram to improve CWE usability
Modifications
Modification Date	Modifier	Organization
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Related_Attack_Patterns
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Common_Consequences, References
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Potential_Mitigations
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Description
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Observed_Examples, Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, Relationships
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Demonstrative_Examples, Potential_Mitigations
2013-02-21	CWE Content Team	MITRE
2013-02-21	updated Applicable_Platforms, References
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Demonstrative_Examples, Detection_Factors
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Relationships
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Causal_Nature, Demonstrative_Examples, Likelihood_of_Exploit, Modes_of_Introduction, References, Relationships
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated References, Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Related_Attack_Patterns, Relationships
2019-09-19	CWE Content Team	MITRE
2019-09-19	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Relationships
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Demonstrative_Examples
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Relationships
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-06-28	CWE Content Team	MITRE
2022-06-28	updated Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Applicable_Platforms, Demonstrative_Examples, Observed_Examples, References, Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Description, Detection_Factors, Maintenance_Notes, Potential_Mitigations, Taxonomy_Mappings
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Observed_Examples
2024-07-16 (CWE 4.15, 2024-07-16)	CWE Content Team	MITRE
2024-07-16 (CWE 4.15, 2024-07-16)	updated Common_Consequences, Description, Diagram

Weakness ID: 259

Vulnerability Mapping: ALLOWEDThis CWE ID may be used to map to real-world vulnerabilities
Abstraction: VariantVariant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.

View customized information:

Description

The product contains a hard-coded password, which it uses for its own inbound authentication or for outbound communication to external components.

Extended Description

A hard-coded password typically leads to a significant authentication failure that can be difficult for the system administrator to detect. Once detected, it can be difficult to fix, so the administrator may be forced into disabling the product entirely. There are two main variations:

Inbound: the product contains an authentication mechanism that checks for a hard-coded password.

Outbound: the product connects to another system or component, and it contains hard-coded password for connecting to that component.

In the Inbound variant, a default administration account is created, and a simple password is hard-coded into the product and associated with that account. This hard-coded password is the same for each installation of the product, and it usually cannot be changed or disabled by system administrators without manually modifying the program, or otherwise patching the product. If the password is ever discovered or published (a common occurrence on the Internet), then anybody with knowledge of this password can access the product. Finally, since all installations of the product will have the same password, even across different organizations, this enables massive attacks such as worms to take place.

The Outbound variant applies to front-end systems that authenticate with a back-end service. The back-end service may require a fixed password which can be easily discovered. The programmer may simply hard-code those back-end credentials into the front-end product. Any user of that program may be able to extract the password. Client-side systems with hard-coded passwords pose even more of a threat, since the extraction of a password from a binary is usually very simple.

Common Consequences

Scope	Impact	Likelihood
Access Control	Technical Impact: Gain Privileges or Assume Identity If hard-coded passwords are used, it is almost certain that malicious users will gain access through the account in question.

Potential Mitigations

Phase: Architecture and Design

For outbound authentication: store passwords outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible.

Phase: Architecture and Design

For inbound authentication: Rather than hard-code a default username and password for first time logins, utilize a "first login" mode that requires the user to enter a unique strong password.

Phase: Architecture and Design

Perform access control checks and limit which entities can access the feature that requires the hard-coded password. For example, a feature might only be enabled through the system console instead of through a network connection.

Phase: Architecture and Design

For inbound authentication: apply strong one-way hashes to your passwords and store those hashes in a configuration file or database with appropriate access control. That way, theft of the file/database still requires the attacker to try to crack the password. When receiving an incoming password during authentication, take the hash of the password and compare it to the hash that you have saved.

Use randomly assigned salts for each separate hash that you generate. This increases the amount of computation that an attacker needs to conduct a brute-force attack, possibly limiting the effectiveness of the rainbow table method.

Phase: Architecture and Design

For front-end to back-end connections: Three solutions are possible, although none are complete.

The first suggestion involves the use of generated passwords which are changed automatically and must be entered at given time intervals by a system administrator. These passwords will be held in memory and only be valid for the time intervals.

Next, the passwords used should be limited at the back end to only performing actions valid for the front end, as opposed to having full access.

Finally, the messages sent should be tagged and checksummed with time sensitive values so as to prevent replay style attacks.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	798	Use of Hard-coded Credentials
PeerOf	Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource.	321	Use of Hard-coded Cryptographic Key
PeerOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	257	Storing Passwords in a Recoverable Format
CanFollow	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	656	Reliance on Security Through Obscurity

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1010	Authenticate Actors

Relevant to the view "CISQ Quality Measures (2020)" (CWE-1305)

Nature	Type	ID	Name
ChildOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	798	Use of Hard-coded Credentials

Relevant to the view "CISQ Data Protection Measures" (CWE-1340)

Nature	Type	ID	Name
ChildOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	798	Use of Hard-coded Credentials

Modes Of Introduction

Phase	Note
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic.
Architecture and Design

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: ICS/OT (Undetermined Prevalence)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

The following code uses a hard-coded password to connect to a database:

(bad code)

Example Language: Java

...
DriverManager.getConnection(url, "scott", "tiger");
...

(attack code)

javap -c ConnMngr.class

22: ldc #36; //String jdbc:mysql://ixne.com/rxsql
24: ldc #38; //String scott
26: ldc #17; //String tiger

Example 2

The following code is an example of an internal hard-coded password in the back-end:

(bad code)

Example Language: C

int VerifyAdmin(char *password) {

if (strcmp(password, "Mew!")) {

printf("Incorrect Password!\n");
return(0)

}
printf("Entering Diagnostic Mode...\n");
return(1);

}

(bad code)

Example Language: Java

int VerifyAdmin(String password) {

if (!password.equals("Mew!")) {

return(0)

}
//Diagnostic Mode
return(1);

}

Example 3

The following examples show a portion of properties and configuration files for Java and ASP.NET applications. The files include username and password information but they are stored in cleartext.

This Java example shows a properties file with a cleartext username / password pair.

(bad code)

Example Language: Java

# Java Web App ResourceBundle properties file
...
webapp.ldap.username=secretUsername
webapp.ldap.password=secretPassword
...

(bad code)

Example Language: ASP.NET

...
<connectionStrings>

</connectionStrings>
...

Example 4

Multiple vendors used hard-coded credentials in their OT products.

Observed Examples

Reference	Description
CVE-2022-29964	Distributed Control System (DCS) has hard-coded passwords for local shell access
CVE-2021-37555	Telnet service for IoT feeder for dogs and cats has hard-coded password [REF-1288]
CVE-2021-35033	Firmware for a WiFi router uses a hard-coded password for a BusyBox shell, allowing bypass of authentication through the UART port

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)

Detection Methods

Manual Analysis

Note: These may be more effective than strictly automated techniques. This is especially the case with weaknesses that are related to design and business rules.

Black Box

Attach the monitor to the process and perform a login. Using disassembled code, look at the associated instructions and see if any of them appear to be comparing the input to a fixed string or value.

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	254	7PK - Security Features
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	724	OWASP Top Ten 2004 Category A3 - Broken Authentication and Session Management
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	753	2009 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	861	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	950	SFP Secondary Cluster: Hardcoded Sensitive Data
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1152	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 49. Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1353	OWASP Top Ten 2021 Category A07:2021 - Identification and Authentication Failures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1396	Comprehensive Categorization: Access Control

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Maintenance

This entry could be split into multiple variants: an inbound variant (as seen in the second demonstrative example) and an outbound variant (as seen in the first demonstrative example). These variants are likely to have different consequences, detectability, etc. More importantly, from a vulnerability theory perspective, they could be characterized as different behaviors.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
7 Pernicious Kingdoms			Password Management: Hard-Coded Password
CLASP			Use of hard-coded password
OWASP Top Ten 2004	A3	CWE More Specific	Broken Authentication and Session Management
The CERT Oracle Secure Coding Standard for Java (2011)	MSC03-J		Never hard code sensitive information
Software Fault Patterns	SFP33		Hardcoded sensitive data

References

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 19: Use of Weak Password-Based Systems." Page 279. McGraw-Hill. 2010.

[REF-1288] Julia Lokrantz. "Ethical hacking of a Smart Automatic Feed Dispenser". 2021-06-07. <http://kth.diva-portal.org/smash/get/diva2:1561552/FULLTEXT01.pdf>.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	7 Pernicious Kingdoms
2006-07-19 (CWE Draft 3, 2006-07-19)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-08-01		KDM Analytics
2008-08-01	added/updated white box definitions
2008-08-15		Veracode
2008-08-15	Suggested OWASP Top Ten 2004 mapping
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings, Weakness_Ordinalities
2008-10-14	CWE Content Team	MITRE
2008-10-14	updated Description, Potential_Mitigations
2008-11-13	CWE Content Team	MITRE
2008-11-13	Significant description modifications to emphasize different variants.
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Demonstrative_Examples, Description, Maintenance_Notes, Other_Notes, Potential_Mitigations
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Demonstrative_Examples, Description, Maintenance_Notes, Potential_Mitigations, Relationships
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations
2009-07-17	KDM Analytics
2009-07-17	Improved the White_Box_Definition
2009-07-27	CWE Content Team	MITRE
2009-07-27	updated Demonstrative_Examples, Related_Attack_Patterns, White_Box_Definitions
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated Demonstrative_Examples, Description, Detection_Factors, Name, Potential_Mitigations, Relationships
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Applicable_Platforms
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Detection_Factors, Potential_Mitigations
2010-09-27	CWE Content Team	MITRE
2010-09-27	updated Relationships
2010-12-13	CWE Content Team	MITRE
2010-12-13	updated Relationships
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Potential_Mitigations, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated References, Relationships, Taxonomy_Mappings
2012-10-30	CWE Content Team	MITRE
2012-10-30	updated Demonstrative_Examples
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships, Taxonomy_Mappings
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Demonstrative_Examples
2017-01-19	CWE Content Team	MITRE
2017-01-19	updated Related_Attack_Patterns
2017-05-03	CWE Content Team	MITRE
2017-05-03	updated Related_Attack_Patterns
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Causal_Nature, Demonstrative_Examples, Likelihood_of_Exploit, Modes_of_Introduction, Relationships, White_Box_Definitions
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Related_Attack_Patterns
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated References, Relationships, Type
2020-08-20	CWE Content Team	MITRE
2020-08-20	updated Relationships
2020-12-10	CWE Content Team	MITRE
2020-12-10	updated Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Demonstrative_Examples, Maintenance_Notes
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Demonstrative_Examples, Observed_Examples, References
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Applicable_Platforms, Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Observed_Examples
Previous Entry Names
Change Date	Previous Entry Name
2010-02-16	Hard-Coded Password

Weakness ID: 492

View customized information:

Description

Inner classes are translated into classes that are accessible at package scope and may expose code that the programmer intended to keep private to attackers.

Extended Description

Inner classes quietly introduce several security concerns because of the way they are translated into Java bytecode. In Java source code, it appears that an inner class can be declared to be accessible only by the enclosing class, but Java bytecode has no concept of an inner class, so the compiler must transform an inner class declaration into a peer class with package level access to the original outer class. More insidiously, since an inner class can access private fields in its enclosing class, once an inner class becomes a peer class in bytecode, the compiler converts private fields accessed by the inner class into protected fields.

Common Consequences

Scope	Impact	Likelihood
Confidentiality	Technical Impact: Read Application Data "Inner Classes" data confidentiality aspects can often be overcome.

Potential Mitigations

Phase: Implementation

Using sealed classes protects object-oriented encapsulation paradigms and therefore protects code from being extended in unforeseen ways.

Phase: Implementation

Inner Classes do not provide security. Warning: Never reduce the security of the object from an outer class, going to an inner class. If an outer class is final or private, ensure that its inner class is private as well.

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	668	Exposure of Resource to Wrong Sphere

Modes Of Introduction

Phase	Note
Implementation

Applicable Platforms

Languages

Java (Undetermined Prevalence)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

The following Java Applet code mistakenly makes use of an inner class.

(bad code)

Example Language: Java

public final class urlTool extends Applet {

private final class urlHelper {

...

}
...

}

Example 2

The following example shows a basic use of inner classes. The class OuterClass contains the private member inner class InnerClass. The private inner class InnerClass includes the method concat that accesses the private member variables of the class OuterClass to output the value of one of the private member variables of the class OuterClass and returns a string that is a concatenation of one of the private member variables of the class OuterClass, the separator input parameter of the method and the private member variable of the class InnerClass.

(bad code)

Example Language: Java

public class OuterClass {

// private member variables of OuterClass
private String memberOne;
private String memberTwo;

// constructor of OuterClass
public OuterClass(String varOne, String varTwo) {

this.memberOne = varOne;
this.memberTwo = varTwo;

}

// InnerClass is a member inner class of OuterClass
private class InnerClass {

private String innerMemberOne;

public InnerClass(String innerVarOne) {

this.innerMemberOne = innerVarOne;

}

public String concat(String separator) {

// InnerClass has access to private member variables of OuterClass
System.out.println("Value of memberOne is: " + memberOne);
return OuterClass.this.memberTwo + separator + this.innerMemberOne;

}

Although this is an acceptable use of inner classes it demonstrates one of the weaknesses of inner classes that inner classes have complete access to all member variables and methods of the enclosing class even those that are declared private and protected. When inner classes are compiled and translated into Java bytecode the JVM treats the inner class as a peer class with package level access to the enclosing class.

To avoid this weakness of inner classes, consider using either static inner classes, local inner classes, or anonymous inner classes.

The following Java example demonstrates the use of static inner classes using the previous example. The inner class InnerClass is declared using the static modifier that signifies that InnerClass is a static member of the enclosing class OuterClass. By declaring an inner class as a static member of the enclosing class, the inner class can only access other static members and methods of the enclosing class and prevents the inner class from accessing nonstatic member variables and methods of the enclosing class. In this case the inner class InnerClass can only access the static member variable memberTwo of the enclosing class OuterClass but cannot access the nonstatic member variable memberOne.

(good code)

Example Language: Java

public class OuterClass {

// private member variables of OuterClass
private String memberOne;
private static String memberTwo;

// constructor of OuterClass
public OuterClass(String varOne, String varTwo) {

this.memberOne = varOne;
this.memberTwo = varTwo;

}

// InnerClass is a static inner class of OuterClass
private static class InnerClass {

private String innerMemberOne;

public InnerClass(String innerVarOne) {

this.innerMemberOne = innerVarOne;

}
public String concat(String separator) {

// InnerClass only has access to static member variables of OuterClass
return memberTwo + separator + this.innerMemberOne;

}

The only limitation with using a static inner class is that as a static member of the enclosing class the inner class does not have a reference to instances of the enclosing class. For many situations this may not be ideal. An alternative is to use a local inner class or an anonymous inner class as shown in the next examples.

Example 3

In the following example the BankAccount class contains the private member inner class InterestAdder that adds interest to the bank account balance. The start method of the BankAccount class creates an object of the inner class InterestAdder, the InterestAdder inner class implements the ActionListener interface with the method actionPerformed. A Timer object created within the start method of the BankAccount class invokes the actionPerformed method of the InterestAdder class every 30 days to add the interest to the bank account balance based on the interest rate passed to the start method as an input parameter. The inner class InterestAdder needs access to the private member variable balance of the BankAccount class in order to add the interest to the bank account balance.

However as demonstrated in the previous example, because InterestAdder is a non-static member inner class of the BankAccount class, InterestAdder also has access to the private member variables of the BankAccount class - including the sensitive data contained in the private member variables for the bank account owner's name, Social Security number, and the bank account number.

(bad code)

Example Language: Java

public class BankAccount {

// private member variables of BankAccount class
private String accountOwnerName;
private String accountOwnerSSN;
private int accountNumber;
private double balance;

// constructor for BankAccount class
public BankAccount(String accountOwnerName, String accountOwnerSSN,
int accountNumber, double initialBalance, int initialRate)
{

this.accountOwnerName = accountOwnerName;
this.accountOwnerSSN = accountOwnerSSN;
this.accountNumber = accountNumber;
this.balance = initialBalance;
this.start(initialRate);

}

// start method will add interest to balance every 30 days

// creates timer object and interest adding action listener object
public void start(double rate)
{

ActionListener adder = new InterestAdder(rate);
Timer t = new Timer(1000 * 3600 * 24 * 30, adder);
t.start();

}

// InterestAdder is an inner class of BankAccount class

// that implements the ActionListener interface
private class InterestAdder implements ActionListener
{

private double rate;

public InterestAdder(double aRate)
{

this.rate = aRate;

}

public void actionPerformed(ActionEvent event)
{

// update interest
double interest = BankAccount.this.balance * rate / 100;
BankAccount.this.balance += interest;

}

In the following example the InterestAdder class from the above example is declared locally within the start method of the BankAccount class. As a local inner class InterestAdder has its scope restricted to the method (or enclosing block) where it is declared, in this case only the start method has access to the inner class InterestAdder, no other classes including the enclosing class has knowledge of the inner class outside of the start method. This allows the inner class to access private member variables of the enclosing class but only within the scope of the enclosing method or block.

(good code)

Example Language: Java

public class BankAccount {

this.accountOwnerName = accountOwnerName;
this.accountOwnerSSN = accountOwnerSSN;
this.accountNumber = accountNumber;
this.balance = initialBalance;
this.start(initialRate);

}

// start method will add interest to balance every 30 days

// creates timer object and interest adding action listener object
public void start(final double rate)
{

// InterestAdder is a local inner class

// that implements the ActionListener interface
class InterestAdder implements ActionListener
{

public void actionPerformed(ActionEvent event)
{

// update interest
double interest = BankAccount.this.balance * rate / 100;
BankAccount.this.balance += interest;

}

}
ActionListener adder = new InterestAdder();
Timer t = new Timer(1000 * 3600 * 24 * 30, adder);
t.start();

}

A similar approach would be to use an anonymous inner class as demonstrated in the next example. An anonymous inner class is declared without a name and creates only a single instance of the inner class object. As in the previous example the anonymous inner class has its scope restricted to the start method of the BankAccount class.

(good code)

Example Language: Java

public class BankAccount {

this.accountOwnerName = accountOwnerName;
this.accountOwnerSSN = accountOwnerSSN;
this.accountNumber = accountNumber;
this.balance = initialBalance;
this.start(initialRate);

}

// start method will add interest to balance every 30 days

// creates timer object and interest adding action listener object
public void start(final double rate)
{

// anonymous inner class that implements the ActionListener interface
ActionListener adder = new ActionListener()
{

public void actionPerformed(ActionEvent event)
{

double interest = BankAccount.this.balance * rate / 100;
BankAccount.this.balance += interest;

}

};

Timer t = new Timer(1000 * 3600 * 24 * 30, adder);
t.start();

}

Example 4

In the following Java example a simple applet provides the capability for a user to input a URL into a text field and have the URL opened in a new browser window. The applet contains an inner class that is an action listener for the submit button, when the user clicks the submit button the inner class action listener's actionPerformed method will open the URL entered into the text field in a new browser window. As with the previous examples using inner classes in this manner creates a security risk by exposing private variables and methods. Inner classes create an additional security risk with applets as applets are executed on a remote machine through a web browser within the same JVM and therefore may run side-by-side with other potentially malicious code.

(bad code)

public class UrlToolApplet extends Applet {

// private member variables for applet components
private Label enterUrlLabel;
private TextField enterUrlTextField;
private Button submitButton;

// init method that adds components to applet

// and creates button listener object
public void init() {

setLayout(new FlowLayout());
enterUrlLabel = new Label("Enter URL: ");
enterUrlTextField = new TextField("", 20);
submitButton = new Button("Submit");
add(enterUrlLabel);
add(enterUrlTextField);
add(submitButton);
ActionListener submitButtonListener = new SubmitButtonListener();
submitButton.addActionListener(submitButtonListener);

}

// button listener inner class for UrlToolApplet class
private class SubmitButtonListener implements ActionListener {

public void actionPerformed(ActionEvent evt) {

if (evt.getSource() == submitButton) {

String urlString = enterUrlTextField.getText();
URL url = null;
try {

url = new URL(urlString);

} catch (MalformedURLException e) {

System.err.println("Malformed URL: " + urlString);

}
if (url != null) {

getAppletContext().showDocument(url);

}

As with the previous examples a solution to this problem would be to use a static inner class, a local inner class or an anonymous inner class. An alternative solution would be to have the applet implement the action listener rather than using it as an inner class as shown in the following example.

(good code)

Example Language: Java

public class UrlToolApplet extends Applet implements ActionListener {

}

// implementation of actionPerformed method of ActionListener interface
public void actionPerformed(ActionEvent evt) {

if (evt.getSource() == submitButton) {

String urlString = enterUrlTextField.getText();
URL url = null;
try {

url = new URL(urlString);

} catch (MalformedURLException e) {

System.err.println("Malformed URL: " + urlString);

}
if (url != null) {

getAppletContext().showDocument(url);

}

Detection Methods

Automated Static Analysis

Effectiveness: High

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	485	7PK - Encapsulation
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	849	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 6 - Object Orientation (OBJ)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	966	SFP Secondary Cluster: Other Exposures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1139	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 05. Object Orientation (OBJ)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1403	Comprehensive Categorization: Exposed Resource

Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID could be used to map to real-world vulnerabilities)

Reason: Acceptable-Use

Rationale:

This CWE entry is at the Variant level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments:

Notes

Other

Mobile code, in this case a Java Applet, is code that is transmitted across a network and executed on a remote machine. Because mobile code developers have little if any control of the environment in which their code will execute, special security concerns become relevant. One of the biggest environmental threats results from the risk that the mobile code will run side-by-side with other, potentially malicious, mobile code. Because all of the popular web browsers execute code from multiple sources together in the same JVM, many of the security guidelines for mobile code are focused on preventing manipulation of your objects' state and behavior by adversaries who have access to the same virtual machine where your program is running.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Mapped Node Name
7 Pernicious Kingdoms		Mobile Code: Use of Inner Class
CLASP		Publicizing of private data when using inner classes
The CERT Oracle Secure Coding Standard for Java (2011)	OBJ08-J	Do not expose private members of an outer class from within a nested class

References

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	7 Pernicious Kingdoms
2006-07-19 (CWE Draft 3, 2006-07-19)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Common_Consequences, Relationships, Other_Notes, Taxonomy_Mappings
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Demonstrative_Examples
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Demonstrative_Examples, Potential_Mitigations
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Relationships, Taxonomy_Mappings
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Description, Other_Notes
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Relationships
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Description, References, Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Demonstrative_Examples
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated Detection_Factors, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2008-04-11	Mobile Code: Use of Inner Class

Weakness ID: 330

View customized information:

Description

The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Extended Description

When product generates predictable values in a context requiring unpredictability, it may be possible for an attacker to guess the next value that will be generated, and use this guess to impersonate another user or access sensitive information.

Common Consequences

Scope	Impact	Likelihood
Confidentiality Other	Technical Impact: Other When a protection mechanism relies on random values to restrict access to a sensitive resource, such as a session ID or a seed for generating a cryptographic key, then the resource being protected could be accessed by guessing the ID or key.
Access Control Other	Technical Impact: Bypass Protection Mechanism; Other If product relies on unique, unguessable IDs to identify a resource, an attacker might be able to guess an ID for a resource that is owned by another user. The attacker could then read the resource, or pre-create a resource with the same ID to prevent the legitimate program from properly sending the resource to the intended user. For example, a product might maintain session information in a file whose name is based on a username. An attacker could pre-create this file for a victim user, then set the permissions so that the application cannot generate the session for the victim, preventing the victim from using the application.
Access Control	Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity When an authorization or authentication mechanism relies on random values to restrict access to restricted functionality, such as a session ID or a seed for generating a cryptographic key, then an attacker may access the restricted functionality by guessing the ID or key.

Potential Mitigations

Phase: Architecture and Design

Use a well-vetted algorithm that is currently considered to be strong by experts in the field, and select well-tested implementations with adequate length seeds.

In general, if a pseudo-random number generator is not advertised as being cryptographically secure, then it is probably a statistical PRNG and should not be used in security-sensitive contexts.

Pseudo-random number generators can produce predictable numbers if the generator is known and the seed can be guessed. A 256-bit seed is a good starting point for producing a "random enough" number.

Phase: Implementation

Consider a PRNG that re-seeds itself as needed from high quality pseudo-random output sources, such as hardware devices.

Phase: Testing

Phases: Architecture and Design; Requirements

Strategy: Libraries or Frameworks

Use products or modules that conform to FIPS 140-2 [REF-267] to avoid obvious entropy problems. Consult FIPS 140-2 Annex C ("Approved Random Number Generators").

Phase: Testing

Relationships

Relevant to the view "Research Concepts" (CWE-1000)

Nature	Type	ID	Name
ChildOf	Pillar - a weakness that is the most abstract type of weakness and represents a theme for all class/base/variant weaknesses related to it. A Pillar is different from a Category as a Pillar is still technically a type of weakness that describes a mistake, while a Category represents a common characteristic used to group related things.	693	Protection Mechanism Failure
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	331	Insufficient Entropy
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	334	Small Space of Random Values
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	335	Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	338	Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)
ParentOf	Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	340	Generation of Predictable Numbers or Identifiers
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	344	Use of Invariant Value in Dynamically Changing Context
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1204	Generation of Weak Initialization Vector (IV)
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1241	Use of Predictable Algorithm in Random Number Generator
CanPrecede	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	804	Guessable CAPTCHA

Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1003	Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	331	Insufficient Entropy
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	335	Incorrect Usage of Seeds in Pseudo-Random Number Generator (PRNG)
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	338	Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Relevant to the view "Architectural Concepts" (CWE-1008)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1013	Encrypt Data

Background Details

Computers are deterministic machines, and as such are unable to produce true randomness. Pseudo-Random Number Generators (PRNGs) approximate randomness algorithmically, starting with a seed from which subsequent values are calculated. There are two types of PRNGs: statistical and cryptographic. Statistical PRNGs provide useful statistical properties, but their output is highly predictable and forms an easy to reproduce numeric stream that is unsuitable for use in cases where security depends on generated values being unpredictable. Cryptographic PRNGs address this problem by generating output that is more difficult to predict. For a value to be cryptographically secure, it must be impossible or highly improbable for an attacker to distinguish between it and a truly random value.

Modes Of Introduction

Phase	Note
Architecture and Design
Implementation	REALIZATION: This weakness is caused during implementation of an architectural security tactic.

Applicable Platforms

Languages

Class: Not Language-Specific (Undetermined Prevalence)

Technologies

Class: Not Technology-Specific (Undetermined Prevalence)

Likelihood Of Exploit

High

Demonstrative Examples

Example 1

This code attempts to generate a unique random identifier for a user's session.

(bad code)

Example Language: PHP

function generateSessionID($userID){

srand($userID);
return rand();

}

Because the seed for the PRNG is always the user's ID, the session ID will always be the same. An attacker could thus predict any user's session ID and potentially hijack the session.

This example also exhibits a Small Seed Space (CWE-339).

Example 2

The following code uses a statistical PRNG to create a URL for a receipt that remains active for some period of time after a purchase.

(bad code)

Example Language: Java

String GenerateReceiptURL(String baseUrl) {

Random ranGen = new Random();
ranGen.setSeed((new Date()).getTime());
return(baseUrl + ranGen.nextInt(400000000) + ".html");

}

This code uses the Random.nextInt() function to generate "unique" identifiers for the receipt pages it generates. Because Random.nextInt() is a statistical PRNG, it is easy for an attacker to guess the strings it generates. Although the underlying design of the receipt system is also faulty, it would be more secure if it used a random number generator that did not produce predictable receipt identifiers, such as a cryptographic PRNG.

Observed Examples

Reference	Description
CVE-2021-3692	PHP framework uses mt_rand() function (Marsenne Twister) when generating tokens
CVE-2020-7010	Cloud application on Kubernetes generates passwords using a weak random number generator based on deployment time.
CVE-2009-3278	Crypto product uses rand() library function to generate a recovery key, making it easier to conduct brute force attacks.
CVE-2009-3238	Random number generator can repeatedly generate the same value.
CVE-2009-2367	Web application generates predictable session IDs, allowing session hijacking.
CVE-2009-2158	Password recovery utility generates a relatively small number of random passwords, simplifying brute force attacks.
CVE-2009-0255	Cryptographic key created with a seed based on the system time.
CVE-2008-5162	Kernel function does not have a good entropy source just after boot.
CVE-2008-4905	Blogging software uses a hard-coded salt when calculating a password hash.
CVE-2008-4929	Bulletin board application uses insufficiently random names for uploaded files, allowing other users to access private files.
CVE-2008-3612	Handheld device uses predictable TCP sequence numbers, allowing spoofing or hijacking of TCP connections.
CVE-2008-2433	Web management console generates session IDs based on the login time, making it easier to conduct session hijacking.
CVE-2008-0166	SSL library uses a weak random number generator that only generates 65,536 unique keys.
CVE-2008-2108	Chain: insufficient precision causes extra zero bits to be assigned, reducing entropy for an API function that generates random numbers.
CVE-2008-2108	Chain: insufficient precision (CWE-1339) in random-number generator causes some zero bits to be reliably generated, reducing the amount of entropy (CWE-331)
CVE-2008-2020	CAPTCHA implementation does not produce enough different images, allowing bypass using a database of all possible checksums.
CVE-2008-0087	DNS client uses predictable DNS transaction IDs, allowing DNS spoofing.
CVE-2008-0141	Application generates passwords that are based on the time of day.

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)

Detection Methods

Black Box

Attach the monitor to the process and look for library functions that indicate when randomness is being used. Run the process multiple times to see if the seed changes. Look for accesses of devices or equivalent resources that are commonly used for strong (or weak) randomness, such as /dev/urandom on Linux. Look for library or system calls that access predictable information such as process IDs and system time.

Automated Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Bytecode Weakness Analysis - including disassembler + source code weakness analysis

Binary Weakness Analysis - including disassembler + source code weakness analysis

Effectiveness: SOAR Partial

Manual Static Analysis - Binary or Bytecode

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Man-in-the-middle attack tool

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Focused Manual Spotcheck - Focused manual analysis of source

Manual Source Code Review (not inspections)

Effectiveness: High

Automated Static Analysis - Source Code

According to SOAR, the following detection techniques may be useful:

Cost effective for partial coverage:

Source code Weakness Analyzer

Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Architecture or Design Review

According to SOAR, the following detection techniques may be useful:

Highly cost effective:

Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Effectiveness: High

Functional Areas

Cryptography
Authentication
Session Management

Memberships

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	254	7PK - Security Features
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	723	OWASP Top Ten 2004 Category A2 - Broken Access Control
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	747	CERT C Secure Coding Standard (2008) Chapter 14 - Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	753	2009 Top 25 - Porous Defenses
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	808	2010 Top 25 - Weaknesses On the Cusp
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	861	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 18 - Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	867	2011 Top 25 - Weaknesses On the Cusp
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	883	CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	905	SFP Primary Cluster: Predictability
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1152	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 49. Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1169	SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1170	SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC)
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1346	OWASP Top Ten 2021 Category A02:2021 - Cryptographic Failures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1366	ICS Communications: Frail Security in Protocols
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1414	Comprehensive Categorization: Randomness

Vulnerability Mapping Notes

Usage: DISCOURAGED

(this CWE ID should not be used to map to real-world vulnerabilities)

Reason: Abstraction

Rationale:

This CWE entry is a level-1 Class (i.e., a child of a Pillar). It might have lower-level children that would be more appropriate

Comments:

Examine children of this entry to see if there is a better fit

Notes

Relationship

This can be primary to many other weaknesses such as cryptographic errors, authentication errors, symlink following, information leaks, and others.

Maintenance

As of CWE 4.3, CWE-330 and its descendants are being investigated by the CWE crypto team to identify gaps related to randomness and unpredictability, as well as the relationships between randomness and cryptographic primitives. This "subtree analysis" might result in the addition or deprecation of existing entries; the reorganization of relationships in some views, e.g. the research view (CWE-1000); more consistent use of terminology; and/or significant modifications to related entries.

Maintenance

As of CWE 4.5, terminology related to randomness, entropy, and predictability can vary widely. Within the developer and other communities, "randomness" is used heavily. However, within cryptography, "entropy" is distinct, typically implied as a measurement. There are no commonly-used definitions, even within standards documents and cryptography papers. Future versions of CWE will attempt to define these terms and, if necessary, distinguish between them in ways that are appropriate for different communities but do not reduce the usability of CWE for mapping, understanding, or other scenarios.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
PLOVER			Randomness and Predictability
7 Pernicious Kingdoms			Insecure Randomness
OWASP Top Ten 2004	A2	CWE More Specific	Broken Access Control
CERT C Secure Coding	CON33-C	Imprecise	Avoid race conditions when using library functions
CERT C Secure Coding	MSC30-C	CWE More Abstract	Do not use the rand() function for generating pseudorandom numbers
CERT C Secure Coding	MSC32-C	CWE More Abstract	Properly seed pseudorandom number generators
WASC	11		Brute Force
WASC	18		Credential/Session Prediction
The CERT Oracle Secure Coding Standard for Java (2011)	MSC02-J		Generate strong random numbers

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-112	Brute Force
CAPEC-485	Signature Spoofing by Key Recreation
CAPEC-59	Session Credential Falsification through Prediction

References

[REF-207] John Viega and Gary McGraw. "Building Secure Software: How to Avoid Security Problems the Right Way". 1st Edition. Addison-Wesley. 2002.

[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 8, "Using Poor Random Numbers" Page 259. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 20: Weak Random Numbers." Page 299. McGraw-Hill. 2010.

Content History

Submissions
Submission Date	Submitter	Organization
2006-07-19 (CWE Draft 3, 2006-07-19)	PLOVER
2006-07-19 (CWE Draft 3, 2006-07-19)
Modifications
Modification Date	Modifier	Organization
2008-07-01	Eric Dalci	Cigital
2008-07-01	updated Time_of_Introduction
2008-09-08	CWE Content Team	MITRE
2008-09-08	updated Background_Details, Relationships, Other_Notes, Relationship_Notes, Taxonomy_Mappings, Weakness_Ordinalities
2008-11-24	CWE Content Team	MITRE
2008-11-24	updated Relationships, Taxonomy_Mappings
2009-01-12	CWE Content Team	MITRE
2009-01-12	updated Description, Likelihood_of_Exploit, Other_Notes, Potential_Mitigations, Relationships
2009-03-10	CWE Content Team	MITRE
2009-03-10	updated Potential_Mitigations
2009-05-27	CWE Content Team	MITRE
2009-05-27	updated Demonstrative_Examples, Related_Attack_Patterns
2009-12-28	CWE Content Team	MITRE
2009-12-28	updated Applicable_Platforms, Common_Consequences, Description, Observed_Examples, Potential_Mitigations, Time_of_Introduction
2010-02-16	CWE Content Team	MITRE
2010-02-16	updated References, Relationships, Taxonomy_Mappings
2010-04-05	CWE Content Team	MITRE
2010-04-05	updated Related_Attack_Patterns
2010-06-21	CWE Content Team	MITRE
2010-06-21	updated Detection_Factors, Potential_Mitigations
2011-03-29	CWE Content Team	MITRE
2011-03-29	updated Demonstrative_Examples
2011-06-01	CWE Content Team	MITRE
2011-06-01	updated Common_Consequences, Relationships, Taxonomy_Mappings
2011-06-27	CWE Content Team	MITRE
2011-06-27	updated Relationships
2011-09-13	CWE Content Team	MITRE
2011-09-13	updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2012-05-11	CWE Content Team	MITRE
2012-05-11	updated Demonstrative_Examples, Observed_Examples, References, Relationships
2014-02-18	CWE Content Team	MITRE
2014-02-18	updated Related_Attack_Patterns
2014-06-23	CWE Content Team	MITRE
2014-06-23	updated Related_Attack_Patterns
2014-07-30	CWE Content Team	MITRE
2014-07-30	updated Detection_Factors
2015-12-07	CWE Content Team	MITRE
2015-12-07	updated Relationships
2017-11-08	CWE Content Team	MITRE
2017-11-08	updated Functional_Areas, Likelihood_of_Exploit, Modes_of_Introduction, References, Relationships, Taxonomy_Mappings
2018-03-27	CWE Content Team	MITRE
2018-03-27	updated References
2019-01-03	CWE Content Team	MITRE
2019-01-03	updated Relationships, Taxonomy_Mappings
2019-06-20	CWE Content Team	MITRE
2019-06-20	updated Relationships
2020-02-24	CWE Content Team	MITRE
2020-02-24	updated Applicable_Platforms, Description, Relationships
2021-03-15	CWE Content Team	MITRE
2021-03-15	updated Maintenance_Notes, Relationships
2021-07-20	CWE Content Team	MITRE
2021-07-20	updated Demonstrative_Examples, Maintenance_Notes, Observed_Examples
2021-10-28	CWE Content Team	MITRE
2021-10-28	updated Relationships
2022-10-13	CWE Content Team	MITRE
2022-10-13	updated Observed_Examples, Relationships
2023-01-31	CWE Content Team	MITRE
2023-01-31	updated Common_Consequences, Description
2023-04-27	CWE Content Team	MITRE
2023-04-27	updated References, Relationships
2023-06-29	CWE Content Team	MITRE
2023-06-29	updated Mapping_Notes, Relationships
2023-10-26	CWE Content Team	MITRE
2023-10-26	updated Observed_Examples
2024-02-29 (CWE 4.14, 2024-02-29)	CWE Content Team	MITRE
2024-02-29 (CWE 4.14, 2024-02-29)	updated Mapping_Notes
Previous Entry Names
Change Date	Previous Entry Name
2008-04-11	Randomness and Predictability

Common Weakness Enumeration

CWE VIEW: Weaknesses Addressed by The CERT Oracle Secure Coding Standard for Java (2011)

View Components

CWE-349: Acceptance of Extraneous Untrusted Data With Trusted Data

Edit Custom Filter

CWE-770: Allocation of Resources Without Limits or Throttling

Edit Custom Filter

CWE-582: Array Declared Public, Final, and Static

Edit Custom Filter

CWE-405: Asymmetric Resource Consumption (Amplification)

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CWE-289: Authentication Bypass by Alternate Name

Edit Custom Filter

CWE-302: Authentication Bypass by Assumed-Immutable Data

Edit Custom Filter

CWE-589: Call to Non-ubiquitous API

Edit Custom Filter

CWE-572: Call to Thread run() instead of start()

Edit Custom Filter

CWE-300: Channel Accessible by Non-Endpoint

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CWE-319: Cleartext Transmission of Sensitive Information

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CWE-498: Cloneable Class Containing Sensitive Information

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CWE-182: Collapse of Data into Unsafe Value

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CWE-486: Comparison of Classes by Name

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CWE-595: Comparison of Object References Instead of Object Contents

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CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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CWE-766: Critical Data Element Declared Public

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CWE-493: Critical Public Variable Without Final Modifier

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CWE-833: Deadlock

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CWE-397: Declaration of Throws for Generic Exception

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CWE-502: Deserialization of Untrusted Data

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CWE-390: Detection of Error Condition Without Action

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CWE-111: Direct Use of Unsafe JNI

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CWE-369: Divide By Zero

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CWE-609: Double-Checked Locking

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CWE-494: Download of Code Without Integrity Check

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CWE-250: Execution with Unnecessary Privileges

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CWE-586: Explicit Call to Finalize()

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CWE-359: Exposure of Private Personal Information to an Unauthorized Actor

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CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere

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CWE-583: finalize() Method Declared Public

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CWE-568: finalize() Method Without super.finalize()

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CWE-209: Generation of Error Message Containing Sensitive Information

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CWE-703: Improper Check or Handling of Exceptional Conditions

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CWE-460: Improper Cleanup on Thrown Exception

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CWE-116: Improper Encoding or Escaping of Output

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CWE-573: Improper Following of Specification by Caller

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CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)

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CWE-333: Improper Handling of Insufficient Entropy in TRNG

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CWE-230: Improper Handling of Missing Values