CWE entries in this view (graph) are fully or partially eliminated by following the SEI CERT C++ Coding Standard, as published in 2016. This view is no longer being actively maintained, since it statically represents the coding rules as they were in 2016.
Audience
Stakeholder
Description
Software Developers
By following the CERT C++ Secure Coding Standard, 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 C++ Secure Coding Standard, 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.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
869(CERT C++ Secure Coding Section 01 - Preprocessor (PRE))
Weaknesses in this category are related to rules in the Preprocessor (PRE) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
870(CERT C++ Secure Coding Section 02 - Declarations and Initialization (DCL))
Weaknesses in this category are related to rules in the Declarations and Initialization (DCL) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
871(CERT C++ Secure Coding Section 03 - Expressions (EXP))
Weaknesses in this category are related to rules in the Expressions (EXP) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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.
NULL Pointer Dereference
- (476)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
871(CERT C++ Secure Coding Section 03 - Expressions (EXP)) >
476(NULL Pointer Dereference)
The product dereferences a pointer that it expects to be valid but is NULL.
NPDnull derefNPEnil pointer dereference
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 Incorrect Operator
- (480)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
871(CERT C++ Secure Coding Section 03 - Expressions (EXP)) >
480(Use of Incorrect Operator)
The product accidentally uses the wrong operator, which changes the logic in security-relevant ways.
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.
Incorrect Short Circuit Evaluation
- (768)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
871(CERT C++ Secure Coding Section 03 - Expressions (EXP)) >
768(Incorrect Short Circuit Evaluation)
The product contains a conditional statement with multiple logical expressions in which one of the non-leading expressions may produce side effects. This may lead to an unexpected state in the program after the execution of the conditional, because short-circuiting logic may prevent the side effects from occurring.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT))
Weaknesses in this category are related to rules in the Integers (INT) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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 Validation of Array Index
- (129)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
129(Improper Validation of Array Index)
The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
out-of-bounds array indexindex-out-of-rangearray index underflow
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.
Integer Overflow or Wraparound
- (190)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
190(Integer Overflow or Wraparound)
The product performs a calculation that can
produce an integer overflow or wraparound when the logic
assumes that the resulting value will always be larger than
the original value. This occurs when an integer value is
incremented to a value that is too large to store in the
associated representation. When this occurs, the value may
become a very small or negative number.
OverflowWraparoundwrap, wrap-around, wrap around
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.
Integer Coercion Error
- (192)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
192(Integer Coercion Error)
Integer coercion refers to a set of flaws pertaining to the type casting, extension, or truncation of primitive data types.
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.
Numeric Truncation Error
- (197)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
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.
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 Input Validation
- (20)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
20(Improper Input Validation)
The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.
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.
Divide By Zero
- (369)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
369(Divide By Zero)
The product divides a value by zero.
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.
Return of Pointer Value Outside of Expected Range
- (466)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
466(Return of Pointer Value Outside of Expected Range)
A function can return a pointer to memory that is outside of the buffer that the pointer is expected to reference.
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.
Assignment of a Fixed Address to a Pointer
- (587)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
587(Assignment of a Fixed Address to a Pointer)
The product sets a pointer to a specific address other than NULL or 0.
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.
Unchecked Input for Loop Condition
- (606)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
606(Unchecked Input for Loop Condition)
The product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.
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 Potentially Dangerous Function
- (676)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
676(Use of Potentially Dangerous Function)
The product invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
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.
Incorrect Conversion between Numeric Types
- (681)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
681(Incorrect Conversion between Numeric Types)
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.
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.
Incorrect Calculation
- (682)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
872(CERT C++ Secure Coding Section 04 - Integers (INT)) >
682(Incorrect Calculation)
The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
873(CERT C++ Secure Coding Section 05 - Floating Point Arithmetic (FLP))
Weaknesses in this category are related to rules in the Floating Point Arithmetic (FLP) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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.
Divide By Zero
- (369)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
873(CERT C++ Secure Coding Section 05 - Floating Point Arithmetic (FLP)) >
369(Divide By Zero)
The product divides a value by zero.
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.
Incorrect Conversion between Numeric Types
- (681)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
873(CERT C++ Secure Coding Section 05 - Floating Point Arithmetic (FLP)) >
681(Incorrect Conversion between Numeric Types)
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.
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.
Incorrect Calculation
- (682)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
873(CERT C++ Secure Coding Section 05 - Floating Point Arithmetic (FLP)) >
682(Incorrect Calculation)
The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.
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.
Function Call With Incorrect Argument Type
- (686)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
873(CERT C++ Secure Coding Section 05 - Floating Point Arithmetic (FLP)) >
686(Function Call With Incorrect Argument Type)
The product calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
874(CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR))
Weaknesses in this category are related to rules in the Arrays and the STL (ARR) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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 Restriction of Operations within the Bounds of a Memory Buffer
- (119)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
874(CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)) >
119(Improper Restriction of Operations within the Bounds of a Memory Buffer)
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
Buffer Overflowbuffer overrunmemory safety
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 Validation of Array Index
- (129)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
874(CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)) >
129(Improper Validation of Array Index)
The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
out-of-bounds array indexindex-out-of-rangearray index underflow
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.
Use of sizeof() on a Pointer Type
- (467)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
874(CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)) >
467(Use of sizeof() on a Pointer Type)
The code calls sizeof() on a pointer type, which can be an incorrect calculation if the programmer intended to determine the size of the data that is being pointed to.
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 Pointer Subtraction to Determine Size
- (469)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
874(CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)) >
469(Use of Pointer Subtraction to Determine Size)
The product subtracts one pointer from another in order to determine size, but this calculation can be incorrect if the pointers do not exist in the same memory chunk.
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 Initialization
- (665)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
874(CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)) >
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.
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.
Buffer Access with Incorrect Length Value
- (805)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
874(CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)) >
805(Buffer Access with Incorrect Length Value)
The product uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR))
Weaknesses in this category are related to rules in the Characters and Strings (STR) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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 Restriction of Operations within the Bounds of a Memory Buffer
- (119)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
119(Improper Restriction of Operations within the Bounds of a Memory Buffer)
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
Buffer Overflowbuffer overrunmemory safety
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.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
- (120)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
120(Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'))
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.
Classic Buffer OverflowUnbounded Transfer
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.
Improper Null Termination
- (170)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
170(Improper Null Termination)
The product does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator.
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.
Off-by-one Error
- (193)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
193(Off-by-one Error)
A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.
off-by-five
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.
Addition of Data Structure Sentinel
- (464)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
464(Addition of Data Structure Sentinel)
The accidental addition of a data-structure sentinel can cause serious programming logic problems.
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.
Function Call With Incorrect Argument Type
- (686)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
686(Function Call With Incorrect Argument Type)
The product calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses.
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.
Incorrect Type Conversion or Cast
- (704)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
704(Incorrect Type Conversion or Cast)
The product does not correctly convert an object, resource, or structure from one type to a different type.
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.
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
- (78)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
78(Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'))
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
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.
Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
- (88)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
875(CERT C++ Secure Coding Section 07 - Characters and Strings (STR)) >
88(Improper Neutralization of Argument Delimiters in a Command ('Argument Injection'))
The product constructs a string for a command to be executed by a separate component
in another control sphere, but it does not properly delimit the
intended arguments, options, or switches within that command string.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM))
Weaknesses in this category are related to rules in the Memory Management (MEM) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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 Restriction of Operations within the Bounds of a Memory Buffer
- (119)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
119(Improper Restriction of Operations within the Bounds of a Memory Buffer)
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
Buffer Overflowbuffer overrunmemory safety
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.
Wrap-around Error
- (128)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
128(Wrap-around Error)
Wrap around errors occur whenever a value is incremented past the maximum value for its type and therefore "wraps around" to a very small, negative, or undefined value.
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.
Incorrect Calculation of Buffer Size
- (131)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
131(Incorrect Calculation of Buffer Size)
The product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.
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.
Integer Overflow or Wraparound
- (190)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
190(Integer Overflow or Wraparound)
The product performs a calculation that can
produce an integer overflow or wraparound when the logic
assumes that the resulting value will always be larger than
the original value. This occurs when an integer value is
incremented to a value that is too large to store in the
associated representation. When this occurs, the value may
become a very small or negative number.
OverflowWraparoundwrap, wrap-around, wrap around
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 Input Validation
- (20)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
20(Improper Input Validation)
The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.
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.
Sensitive Information in Resource Not Removed Before Reuse
- (226)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
226(Sensitive Information in Resource Not Removed Before Reuse)
The product releases a resource such as memory or a file so that it can be made available for reuse, but it does not clear or "zeroize" the information contained in the resource before the product performs a critical state transition or makes the resource available for reuse by other entities.
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 Clearing of Heap Memory Before Release ('Heap Inspection')
- (244)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
244(Improper Clearing of Heap Memory Before Release ('Heap Inspection'))
Using realloc() to resize buffers that store sensitive information can leave the sensitive information exposed to attack, because it is not removed from memory.
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.
Unchecked Return Value
- (252)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
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.
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.
Unchecked Error Condition
- (391)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
391(Unchecked Error Condition)
[PLANNED FOR DEPRECATION. SEE MAINTENANCE NOTES AND CONSIDER CWE-252, CWE-248, OR CWE-1069.] Ignoring exceptions and other error conditions may allow an attacker to induce unexpected behavior unnoticed.
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 Resource Shutdown or Release
- (404)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
404(Improper Resource Shutdown or Release)
The product does not release or incorrectly releases a resource before it is made available for re-use.
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.
Double Free
- (415)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
415(Double Free)
The product calls free() twice on the same memory address.
Double-free
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.
Use After Free
- (416)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
416(Use After Free)
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Dangling pointerUAFUse-After-Free
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.
NULL Pointer Dereference
- (476)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
476(NULL Pointer Dereference)
The product dereferences a pointer that it expects to be valid but is NULL.
NPDnull derefNPEnil pointer dereference
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.
Exposure of Core Dump File to an Unauthorized Control Sphere
- (528)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
528(Exposure of Core Dump File to an Unauthorized Control Sphere)
The product generates a core dump file in a directory, archive, or other resource that is stored, transferred, or otherwise made accessible to unauthorized actors.
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.
Free of Memory not on the Heap
- (590)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
590(Free of Memory not on the Heap)
The product calls free() on a pointer to memory that was not allocated using associated heap allocation functions such as malloc(), calloc(), or realloc().
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.
Sensitive Data Storage in Improperly Locked Memory
- (591)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
591(Sensitive Data Storage in Improperly Locked Memory)
The product stores sensitive data in memory that is not locked, or that has been incorrectly locked, which might cause the memory to be written to swap files on disk by the virtual memory manager. This can make the data more accessible to external actors.
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 Initialization
- (665)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
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.
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.
Function Call With Incorrectly Specified Argument Value
- (687)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
687(Function Call With Incorrectly Specified Argument Value)
The product calls a function, procedure, or routine, but the caller specifies an argument that contains the wrong value, which may lead to resultant weaknesses.
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)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
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)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
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.
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 Check for Unusual or Exceptional Conditions
- (754)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
754(Improper Check for Unusual or Exceptional Conditions)
The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.
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.
Mismatched Memory Management Routines
- (762)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
762(Mismatched Memory Management Routines)
The product attempts to return a memory resource to the system, but it calls a release function that is not compatible with the function that was originally used to allocate that resource.
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.
Allocation of Resources Without Limits or Throttling
- (770)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
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.
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.
Untrusted Pointer Dereference
- (822)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
876(CERT C++ Secure Coding Section 08 - Memory Management (MEM)) >
822(Untrusted Pointer Dereference)
The product obtains a value from an untrusted source, converts this value to a pointer, and dereferences the resulting pointer.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO))
Weaknesses in this category are related to rules in the Input Output (FIO) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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 Restriction of Operations within the Bounds of a Memory Buffer
- (119)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
119(Improper Restriction of Operations within the Bounds of a Memory Buffer)
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
Buffer Overflowbuffer overrunmemory safety
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)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
134(Use of Externally-Controlled Format String)
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
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.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- (22)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
22(Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'))
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Directory traversalPath traversal
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.
Improper Handling of Unexpected Data Type
- (241)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
241(Improper Handling of Unexpected Data Type)
The product does not handle or incorrectly handles when a particular element is not the expected type, e.g. it expects a digit (0-9) but is provided with a letter (A-Z).
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.
Incorrect Default Permissions
- (276)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
276(Incorrect Default Permissions)
During installation, installed file permissions are set to allow anyone to modify those files.
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.
Incorrect Execution-Assigned Permissions
- (279)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
279(Incorrect Execution-Assigned Permissions)
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.
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.
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
- (362)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
362(Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'))
The product contains a concurrent code sequence that 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 operating concurrently.
Race Condition
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.
Time-of-check Time-of-use (TOCTOU) Race Condition
- (367)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
367(Time-of-check Time-of-use (TOCTOU) Race Condition)
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state.
TOCTTOUTOCCTOU
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.
Path Traversal: '/absolute/pathname/here'
- (37)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
37(Path Traversal: '/absolute/pathname/here')
The product accepts input in the form of a slash absolute path ('/absolute/pathname/here') without appropriate validation, which can allow an attacker to traverse the file system to unintended locations or access arbitrary files.
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.
Creation of Temporary File in Directory with Insecure Permissions
- (379)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
379(Creation of Temporary File in Directory with Insecure Permissions)
The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.
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.
Path Traversal: '\absolute\pathname\here'
- (38)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
38(Path Traversal: '\absolute\pathname\here')
The product accepts input in the form of a backslash absolute path ('\absolute\pathname\here') without appropriate validation, which can allow an attacker to traverse the file system to unintended locations or access arbitrary files.
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.
Path Traversal: 'C:dirname'
- (39)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
39(Path Traversal: 'C:dirname')
The product accepts input that contains a drive letter or Windows volume letter ('C:dirname') that potentially redirects access to an unintended location or arbitrary file.
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.
Unchecked Error Condition
- (391)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
391(Unchecked Error Condition)
[PLANNED FOR DEPRECATION. SEE MAINTENANCE NOTES AND CONSIDER CWE-252, CWE-248, OR CWE-1069.] Ignoring exceptions and other error conditions may allow an attacker to induce unexpected behavior unnoticed.
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.
Exposure of File Descriptor to Unintended Control Sphere ('File Descriptor Leak')
- (403)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
403(Exposure of File Descriptor to Unintended Control Sphere ('File Descriptor Leak'))
A process does not close sensitive file descriptors before invoking a child process, which allows the child to perform unauthorized I/O operations using those descriptors.
File descriptor leak
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 Resource Shutdown or Release
- (404)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
404(Improper Resource Shutdown or Release)
The product does not release or incorrectly releases a resource before it is made available for re-use.
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.
Improper Resolution of Path Equivalence
- (41)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
41(Improper Resolution of Path Equivalence)
The product is vulnerable to file system contents disclosure through path equivalence. Path equivalence involves the use of special characters in file and directory names. The associated manipulations are intended to generate multiple names for the same object.
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.
Files or Directories Accessible to External Parties
- (552)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
552(Files or Directories Accessible to External Parties)
The product makes files or directories accessible to unauthorized actors, even though they should not be.
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.
Improper Link Resolution Before File Access ('Link Following')
- (59)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
59(Improper Link Resolution Before File Access ('Link Following'))
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
insecure temporary fileZip Slip
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.
UNIX Hard Link
- (62)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
62(UNIX Hard Link)
The product, when opening a file or directory, does not sufficiently account for when the name is associated with a hard link to a target that is outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.
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.
Windows Shortcut Following (.LNK)
- (64)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
64(Windows Shortcut Following (.LNK))
The product, when opening a file or directory, does not sufficiently handle when the file is a Windows shortcut (.LNK) whose target is outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.
Windows symbolic link followingsymlink
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.
Windows Hard Link
- (65)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
65(Windows Hard Link)
The product, when opening a file or directory, does not sufficiently handle when the name is associated with a hard link to a target that is outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.
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 Handling of Windows Device Names
- (67)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
67(Improper Handling of Windows Device Names)
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.
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.
Multiple Operations on Resource in Single-Operation Context
- (675)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
675(Multiple Operations on Resource in Single-Operation Context)
The product performs the same operation on a resource two or more times, when the operation should only be applied once.
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 Potentially Dangerous Function
- (676)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
676(Use of Potentially Dangerous Function)
The product invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
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.
External Control of File Name or Path
- (73)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - Input Output (FIO)) >
73(External Control of File Name or Path)
The product allows user input to control or influence paths or file names that are used in filesystem operations.
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.
Incorrect Permission Assignment for Critical Resource
- (732)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - 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.
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.
Allocation of Resources Without Limits or Throttling
- (770)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
877(CERT C++ Secure Coding Section 09 - 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.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
878(CERT C++ Secure Coding Section 10 - Environment (ENV))
Weaknesses in this category are related to rules in the Environment (ENV) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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 Restriction of Operations within the Bounds of a Memory Buffer
- (119)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
878(CERT C++ Secure Coding Section 10 - Environment (ENV)) >
119(Improper Restriction of Operations within the Bounds of a Memory Buffer)
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
Buffer Overflowbuffer overrunmemory safety
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.
Untrusted Search Path
- (426)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
878(CERT C++ Secure Coding Section 10 - Environment (ENV)) >
426(Untrusted Search Path)
The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product's direct control.
Untrusted Path
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.
Duplicate Key in Associative List (Alist)
- (462)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
878(CERT C++ Secure Coding Section 10 - Environment (ENV)) >
462(Duplicate Key in Associative List (Alist))
Duplicate keys in associative lists can lead to non-unique keys being mistaken for an error.
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.
Incorrect Control Flow Scoping
- (705)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
878(CERT C++ Secure Coding Section 10 - Environment (ENV)) >
705(Incorrect Control Flow Scoping)
The product does not properly return control flow to the proper location after it has completed a task or detected an unusual condition.
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.
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
- (78)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
878(CERT C++ Secure Coding Section 10 - Environment (ENV)) >
78(Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'))
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
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.
Reliance on Untrusted Inputs in a Security Decision
- (807)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
878(CERT C++ Secure Coding Section 10 - Environment (ENV)) >
807(Reliance on Untrusted Inputs in a Security Decision)
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.
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.
Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
- (88)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
878(CERT C++ Secure Coding Section 10 - Environment (ENV)) >
88(Improper Neutralization of Argument Delimiters in a Command ('Argument Injection'))
The product constructs a string for a command to be executed by a separate component
in another control sphere, but it does not properly delimit the
intended arguments, options, or switches within that command string.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
879(CERT C++ Secure Coding Section 11 - Signals (SIG))
Weaknesses in this category are related to rules in the Signals (SIG) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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.
Signal Handler Use of a Non-reentrant Function
- (479)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
879(CERT C++ Secure Coding Section 11 - Signals (SIG)) >
479(Signal Handler Use of a Non-reentrant Function)
The product defines a signal handler that calls a non-reentrant function.
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 Synchronization
- (662)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
879(CERT C++ Secure Coding Section 11 - Signals (SIG)) >
662(Improper Synchronization)
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.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR))
Weaknesses in this category are related to rules in the Exceptions and Error Handling (ERR) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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.
Generation of Error Message Containing Sensitive Information
- (209)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (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.
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.
Detection of Error Condition Without Action
- (390)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)) >
390(Detection of Error Condition Without Action)
The product detects a specific error, but takes no actions to handle the error.
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.
Unchecked Error Condition
- (391)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)) >
391(Unchecked Error Condition)
[PLANNED FOR DEPRECATION. SEE MAINTENANCE NOTES AND CONSIDER CWE-252, CWE-248, OR CWE-1069.] Ignoring exceptions and other error conditions may allow an attacker to induce unexpected behavior unnoticed.
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.
Improper Cleanup on Thrown Exception
- (460)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)) >
460(Improper Cleanup on Thrown Exception)
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.
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.
Exposure of Sensitive System Information to an Unauthorized Control Sphere
- (497)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (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.
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.
Missing Standardized Error Handling Mechanism
- (544)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)) >
544(Missing Standardized Error Handling Mechanism)
The product does not use a standardized method for handling errors throughout the code, which might introduce inconsistent error handling and resultant weaknesses.
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)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (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.
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.
Incorrect Control Flow Scoping
- (705)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)) >
705(Incorrect Control Flow Scoping)
The product does not properly return control flow to the proper location after it has completed a task or detected an unusual condition.
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 Check for Unusual or Exceptional Conditions
- (754)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)) >
754(Improper Check for Unusual or Exceptional Conditions)
The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.
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 Handling of Exceptional Conditions
- (755)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
880(CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)) >
755(Improper Handling of Exceptional Conditions)
The product does not handle or incorrectly handles an exceptional condition.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
881(CERT C++ Secure Coding Section 13 - Object Oriented Programming (OOP))
Weaknesses in this category are related to rules in the Object Oriented Programming (OOP) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
882(CERT C++ Secure Coding Section 14 - Concurrency (CON))
Weaknesses in this category are related to rules in the Concurrency (CON) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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.
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
- (362)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
882(CERT C++ Secure Coding Section 14 - Concurrency (CON)) >
362(Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'))
The product contains a concurrent code sequence that 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 operating concurrently.
Race Condition
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.
Race Condition within a Thread
- (366)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
882(CERT C++ Secure Coding Section 14 - Concurrency (CON)) >
366(Race Condition within a Thread)
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.
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 Resource Shutdown or Release
- (404)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
882(CERT C++ Secure Coding Section 14 - Concurrency (CON)) >
404(Improper Resource Shutdown or Release)
The product does not release or incorrectly releases a resource before it is made available for re-use.
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.
Exposure of Data Element to Wrong Session
- (488)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
882(CERT C++ Secure Coding Section 14 - Concurrency (CON)) >
488(Exposure of Data Element to Wrong Session)
The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.
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.
Missing Release of Resource after Effective Lifetime
- (772)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
882(CERT C++ Secure Coding Section 14 - Concurrency (CON)) >
772(Missing Release of Resource after Effective Lifetime)
The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC))
Weaknesses in this category are related to rules in the Miscellaneous (MSC) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
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)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
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
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.
Compiler Removal of Code to Clear Buffers
- (14)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
14(Compiler Removal of Code to Clear Buffers)
Sensitive memory is cleared according to the source code, but compiler optimizations leave the memory untouched when it is not read from again, aka "dead store removal."
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 Handling of Unicode Encoding
- (176)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
176(Improper Handling of Unicode Encoding)
The product does not properly handle when an input contains Unicode encoding.
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 Input Validation
- (20)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
20(Improper Input Validation)
The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.
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.
Use of a Broken or Risky Cryptographic Algorithm
- (327)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
327(Use of a Broken or Risky Cryptographic Algorithm)
The product uses a broken or risky cryptographic algorithm or protocol.
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.
Use of Insufficiently Random Values
- (330)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
330(Use of Insufficiently Random Values)
The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.
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 Incorrect Operator
- (480)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
480(Use of Incorrect Operator)
The product accidentally uses the wrong operator, which changes the logic in security-relevant ways.
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.
Comparing instead of Assigning
- (482)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
482(Comparing instead of Assigning)
The code uses an operator for comparison when the intention was to perform an assignment.
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.
Dead Code
- (561)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
561(Dead Code)
The product contains dead code, which can never be executed.
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.
Assignment to Variable without Use
- (563)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
563(Assignment to Variable without Use)
The variable's value is assigned but never used, making it a dead store.
Unused Variable
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.
Expression is Always False
- (570)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
570(Expression is Always False)
The product contains an expression that will always evaluate to false.
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.
Expression is Always True
- (571)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
571(Expression is Always True)
The product contains an expression that will always evaluate to true.
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.
Incorrect Comparison
- (697)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
697(Incorrect Comparison)
The product compares two entities in a security-relevant context, but the comparison is incorrect, which may lead to resultant weaknesses.
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.
Incorrect Type Conversion or Cast
- (704)
868(Weaknesses Addressed by the SEI CERT C++ Coding Standard (2016 Version)) >
883(CERT C++ Secure Coding Section 49 - Miscellaneous (MSC)) >
704(Incorrect Type Conversion or Cast)
The product does not correctly convert an object, resource, or structure from one type to a different type.
(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.
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:
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Description
The accidental addition of a data-structure sentinel can cause serious programming logic problems.
Extended Description
Data-structure sentinels are often used to mark the structure of data. A common example of this is the null character at the end of strings or a special sentinel to mark the end of a linked list. It is dangerous to allow this type of control data to be easily accessible. Therefore, it is important to protect from the addition or modification of sentinels.
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.
Impact
Details
Modify Application Data
Scope: Integrity
Generally this error will cause the data structure to not work properly by truncating the data.
Potential Mitigations
Phase(s)
Mitigation
Implementation; Architecture and Design
Encapsulate the user from interacting with data sentinels. Validate user input to verify that sentinels are not present.
Implementation
Proper error checking can reduce the risk of inadvertently introducing sentinel values into data. For example, if a parsing function fails or encounters an error, it might return a value that is the same as the sentinel.
Architecture and Design
Use an abstraction library to abstract away risky APIs. This is not a complete solution.
Operation
Use OS-level preventative functionality. This is not a complete solution.
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" (View-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.
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.
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.
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
Implementation
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
C
(Undetermined Prevalence)
C++
(Undetermined Prevalence)
Likelihood Of Exploit
High
Demonstrative Examples
Example 1
The following example assigns some character values to a list of characters and prints them each individually, and then as a string. The third character value is intended to be an integer taken from user input and converted to an int.
The first print statement will print each character separated by a space. However, if a NULL byte is read from stdin by fgetc, then it will return 0. When foo is printed as a string, the 0 at character foo[2] will act as a NULL terminator and foo[3] will never be printed.
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.
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CLASP
Addition of data-structure sentinel
CERT C Secure Coding
STR03-C
Do not inadvertently truncate a null-terminated byte string
CERT C Secure Coding
STR06-C
Do not assume that strtok() leaves the parse string unchanged
CWE-770: Allocation of Resources Without Limits or Throttling
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.
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Description
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.
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.
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource.
Potential Mitigations
Phase(s)
Mitigation
Requirements
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
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.
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.
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.
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.
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.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
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.
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" (View-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.
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.
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.
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.
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.
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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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.
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.
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)
}
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
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).
Go-based workload orchestrator does not limit resource usage with unauthenticated connections, allowing a DoS by flooding the service
Detection
Methods
Method
Details
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.
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).
(this CWE ID may 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
Fit
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)
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>.
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
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
Contributed or reviewed taxonomy mappings for ISA/IEC 62443
CWE-587: Assignment of a Fixed Address to a Pointer
Weakness ID: 587
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:
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Description
The product sets a pointer to a specific address other than NULL or 0.
Extended Description
Using a fixed address is not portable, because that address will probably not be valid in all environments or platforms.
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.
Impact
Details
Execute Unauthorized Code or Commands
Scope: Integrity, Confidentiality, Availability
If one executes code at a known location, an attacker might be able to inject code there beforehand.
DoS: Crash, Exit, or Restart; Reduce Maintainability; Reduce Reliability
Scope: Availability
If the code is ported to another platform or environment, the pointer is likely to be invalid and cause a crash.
Read Memory; Modify Memory
Scope: Confidentiality, Integrity
The data at a known pointer location can be easily read or influenced by an attacker.
Potential Mitigations
Phase(s)
Mitigation
Implementation
Never set a pointer to a fixed address.
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" (View-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.
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.
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
Implementation
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
C
(Undetermined Prevalence)
C++
(Undetermined Prevalence)
C#
(Undetermined Prevalence)
Class: Assembly
(Undetermined Prevalence)
Demonstrative Examples
Example 1
This code assumes a particular function will always be found at a particular address. It assigns a pointer to that address and calls the function.
(bad code)
Example Language: C
int (*pt2Function) (float, char, char)=0x08040000; int result2 = (*pt2Function) (12, 'a', 'b'); // Here we can inject code to execute.
The same function may not always be found at the same memory address. This could lead to a crash, or an attacker may alter the memory at the expected address, leading to arbitrary code execution.
Weakness Ordinalities
Ordinality
Description
Indirect
(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)
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.
CERT C++ Secure Coding Section 04 - Integers (INT)
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).
(this CWE ID may 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
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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CERT C Secure Coding
INT36-C
Imprecise
Converting a pointer to integer or integer to pointer
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.
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Description
The variable's value is assigned but never used, making it a dead store.
Extended Description
After the assignment, the variable is either assigned another value or goes out of scope. It is likely that the variable is simply vestigial, but it is also possible that the unused variable points out a bug.
Alternate Terms
Unused Variable
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.
Impact
Details
Quality Degradation; Varies by Context
Scope: Other
This weakness could be an indication of a bug in the program or a deprecated variable that was not removed and is an indication of poor quality. This could lead to further bugs and the introduction of weaknesses.
Potential Mitigations
Phase(s)
Mitigation
Implementation
Remove unused variables from the code.
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" (View-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.
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
Implementation
Demonstrative Examples
Example 1
The following code excerpt assigns to the variable r and then overwrites the value without using it.
(bad code)
Example Language: C
r = getName(); r = getNewBuffer(buf);
Weakness Ordinalities
Ordinality
Description
Indirect
(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)
Detection
Methods
Method
Details
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
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.
CERT C++ Secure Coding Section 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).
(this CWE ID may 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.
CWE-805: Buffer Access with Incorrect Length Value
Weakness ID: 805
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.
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Description
The product uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.
Extended Description
When the length value exceeds the size of the destination, a buffer overflow could occur.
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.
Impact
Details
Read Memory; Modify Memory; Execute Unauthorized Code or Commands
Scope: Integrity, Confidentiality, Availability
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. This can often be used to subvert any other security service.
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Potential Mitigations
Phase(s)
Mitigation
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, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.
Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
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.
Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.
Note: This is not a complete solution, since many buffer overflows are not related to strings.
Operation; Build and Compilation
Strategy: Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.
D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
Effectiveness: Defense in Depth
Note:
This is not necessarily a complete solution, since these mechanisms only detect certain types of overflows. In addition, the result is still a denial of service, since the typical response is to exit the application.
Implementation
Consider adhering to the following rules when allocating and managing an application's memory:
Double check that the buffer is as large as specified.
When using functions that accept a number of bytes to copy, such as strncpy(), be aware that if the destination buffer size is equal to the source buffer size, it may not NULL-terminate the string.
Check buffer boundaries if accessing the buffer in a loop and make sure there is no danger of writing past the allocated space.
If necessary, truncate all input strings to a reasonable length before passing them to the copy and concatenation functions.
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.
Operation; Build and Compilation
Strategy: Environment Hardening
Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.
Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing" (for Windows) and "prelinking" (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.
For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].
Effectiveness: Defense in Depth
Note: These techniques do not provide a complete solution. For instance, exploits frequently use a bug that discloses memory addresses in order to maximize reliability of code execution [REF-1337]. It has also been shown that a side-channel attack can bypass ASLR [REF-1333].
Operation
Strategy: Environment Hardening
Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.
For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].
Effectiveness: Defense in Depth
Note: This is not a complete solution, since buffer overflows could be used to overwrite nearby variables to modify the software's state in dangerous ways. In addition, it cannot be used in cases in which self-modifying code is required. Finally, an attack could still cause a denial of service, since the typical response is to exit the application.
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 product or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
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
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" (View-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.
Improper Restriction of Operations within the Bounds of a Memory 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.
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.
Relevant to the view "CISQ Quality Measures (2020)" (View-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.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Relevant to the view "CISQ Data Protection Measures" (View-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.
Improper Restriction of Operations within the Bounds of a Memory Buffer
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
Implementation
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
C
(Often Prevalent)
C++
(Often Prevalent)
Class: Assembly
(Undetermined Prevalence)
Likelihood Of Exploit
High
Demonstrative Examples
Example 1
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.
This function allocates a buffer of 64 bytes to store the hostname under the assumption that the maximum length value of hostname is 64 bytes, however there is no guarantee that the hostname will not be larger than 64 bytes. If an attacker specifies an address which resolves to a very large hostname, then the function may overwrite sensitive data or even relinquish control flow to the attacker.
Note that this example also contains an unchecked return value (CWE-252) that can lead to a NULL pointer dereference (CWE-476).
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,
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
In the following example, the source character string is copied to the dest character string using the method strncpy.
(bad code)
Example Language: C
... char source[21] = "the character string"; char dest[12]; strncpy(dest, source, sizeof(source)-1); ...
However, in the call to strncpy the source character string is used within the sizeof call to determine the number of characters to copy. This will create a buffer overflow as the size of the source character string is greater than the dest character string. The dest character string should be used within the sizeof call to ensure that the correct number of characters are copied, as shown below.
(good code)
Example Language: C
... char source[21] = "the character string"; char dest[12]; strncpy(dest, source, sizeof(dest)-1); ...
Example 4
In this example, the method outputFilenameToLog outputs a filename to a log file. The method arguments include a pointer to a character string containing the file name and an integer for the number of characters in the string. The filename is copied to a buffer where the buffer size is set to a maximum size for inputs to the log file. The method then calls another method to save the contents of the buffer to the log file.
(bad code)
Example Language: C
#define LOG_INPUT_SIZE 40
// saves the file name to a log file int outputFilenameToLog(char *filename, int length) {
int success;
// buffer with size set to maximum size for input to log file char buf[LOG_INPUT_SIZE];
// copy filename to buffer strncpy(buf, filename, length);
// save to log file success = saveToLogFile(buf);
return success;
}
However, in this case the string copy method, strncpy, mistakenly uses the length method argument to determine the number of characters to copy rather than using the size of the local character string, buf. This can lead to a buffer overflow if the number of characters contained in character string pointed to by filename is larger then the number of characters allowed for the local character string. The string copy method should use the buf character string within a sizeof call to ensure that only characters up to the size of the buf array are copied to avoid a buffer overflow, as shown below.
(good code)
Example Language: C
... // copy filename to buffer strncpy(buf, filename, sizeof(buf)-1); ...
Example 5
Windows provides the MultiByteToWideChar(), WideCharToMultiByte(), UnicodeToBytes(), and BytesToUnicode() functions to convert between arbitrary multibyte (usually ANSI) character strings and Unicode (wide character) strings. The size arguments to these functions are specified in different units, (one in bytes, the other in characters) making their use prone to error.
In a multibyte character string, each character occupies a varying number of bytes, and therefore the size of such strings is most easily specified as a total number of bytes. In Unicode, however, characters are always a fixed size, and string lengths are typically given by the number of characters they contain. Mistakenly specifying the wrong units in a size argument can lead to a buffer overflow.
The following function takes a username specified as a multibyte string and a pointer to a structure for user information and populates the structure with information about the specified user. Since Windows authentication uses Unicode for usernames, the username argument is first converted from a multibyte string to a Unicode string.
This function incorrectly passes the size of unicodeUser in bytes instead of characters. The call to MultiByteToWideChar() can therefore write up to (UNLEN+1)*sizeof(WCHAR) wide characters, or (UNLEN+1)*sizeof(WCHAR)*sizeof(WCHAR) bytes, to the unicodeUser array, which has only (UNLEN+1)*sizeof(WCHAR) bytes allocated.
If the username string contains more than UNLEN characters, the call to MultiByteToWideChar() will overflow the buffer unicodeUser.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Language interpreter API function doesn't validate length argument, leading to information exposure
Weakness Ordinalities
Ordinality
Description
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Primary
(where the weakness exists independent of other weaknesses)
Detection
Methods
Method
Details
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 generally does not account for environmental considerations when reporting out-of-bounds memory operations. This can make it difficult for users to determine which warnings should be investigated first. For example, an analysis tool might report buffer overflows that originate from command line arguments in a program that is not expected to run with setuid or other special privileges.
Effectiveness: High
Note:Detection techniques for buffer-related errors are more mature than for most other weakness types.
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
Note:Without visibility into the code, black box methods may not be able to sufficiently distinguish this weakness from others, requiring manual methods to diagnose the underlying problem.
Manual Analysis
Manual analysis can be useful for finding this weakness, but it might not achieve desired code coverage within limited time constraints. This becomes difficult for weaknesses that must be considered for all inputs, since the attack surface can be too large.
Affected Resources
Memory
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.
CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)
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).
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CERT C Secure Coding
ARR38-C
Imprecise
Guarantee that library functions do not form invalid pointers
CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Weakness ID: 120
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:
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.
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Description
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.
Extended Description
A buffer overflow condition exists when a product attempts to put more data in a buffer than it can hold, or when it attempts to put data in a memory area outside of the boundaries of a buffer. The simplest type of error, and the most common cause of buffer overflows, is the "classic" case in which the product copies the buffer without restricting how much is copied. Other variants exist, but the existence of a classic overflow strongly suggests that the programmer is not considering even the most basic of security protections.
Alternate Terms
Classic Buffer Overflow
This term was frequently used by vulnerability researchers during approximately 1995 to 2005 to differentiate buffer copies without length checks (which had been known about for decades) from other emerging weaknesses that still involved invalid accesses of buffers, as vulnerability researchers began to develop advanced exploitation techniques.
Unbounded Transfer
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.
Impact
Details
Modify Memory; Execute Unauthorized Code or Commands
Scope: Integrity, Confidentiality, Availability
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of the product's implicit security policy. This can often be used to subvert any other security service.
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the product into an infinite loop.
Potential Mitigations
Phase(s)
Mitigation
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, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.
Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
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.
Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.
Note: This is not a complete solution, since many buffer overflows are not related to strings.
Operation; Build and Compilation
Strategy: Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.
D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.
Effectiveness: Defense in Depth
Note:
This is not necessarily a complete solution, since these mechanisms only detect certain types of overflows. In addition, the result is still a denial of service, since the typical response is to exit the application.
Implementation
Consider adhering to the following rules when allocating and managing an application's memory:
Double check that your buffer is as large as you specify.
When using functions that accept a number of bytes to copy, such as strncpy(), be aware that if the destination buffer size is equal to the source buffer size, it may not NULL-terminate the string.
Check buffer boundaries if accessing the buffer in a loop and make sure there is no danger of writing past the allocated space.
If necessary, truncate all input strings to a reasonable length before passing them to the copy and concatenation functions.
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.
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.
Operation; Build and Compilation
Strategy: Environment Hardening
Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.
Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing" (for Windows) and "prelinking" (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.
For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].
Effectiveness: Defense in Depth
Note: These techniques do not provide a complete solution. For instance, exploits frequently use a bug that discloses memory addresses in order to maximize reliability of code execution [REF-1337]. It has also been shown that a side-channel attack can bypass ASLR [REF-1333]
Operation
Strategy: Environment Hardening
Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.
For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].
Effectiveness: Defense in Depth
Note: This is not a complete solution, since buffer overflows could be used to overwrite nearby variables to modify the software's state in dangerous ways. In addition, it cannot be used in cases in which self-modifying code is required. Finally, an attack could still cause a denial of service, since the typical response is to exit the application.
Build and Compilation; Operation
Most mitigating technologies at the compiler or OS level to date address only a subset of buffer overflow problems and rarely provide complete protection against even that subset. It is good practice to implement strategies to increase the workload of an attacker, such as leaving the attacker to guess an unknown value that changes every program execution.
Implementation
Replace unbounded copy functions with analogous functions that support length arguments, such as strcpy with strncpy. Create these if they are not available.
Effectiveness: Moderate
Note: This approach is still susceptible to calculation errors, including issues such as off-by-one errors (CWE-193) and incorrectly calculating buffer lengths (CWE-131).
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.
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.
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
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" (View-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.
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.
Use of Path Manipulation Function without Maximum-sized Buffer
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.
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.
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.
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.
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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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.
Improper Restriction of Operations within the Bounds of a Memory Buffer
Relevant to the view "CISQ Quality Measures (2020)" (View-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.
Relevant to the view "CISQ Data Protection Measures" (View-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.
Relevant to the view "Seven Pernicious Kingdoms" (View-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.
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
Implementation
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
C
(Often Prevalent)
C++
(Often Prevalent)
Class: Assembly
(Undetermined Prevalence)
Likelihood Of Exploit
High
Demonstrative Examples
Example 1
The following code asks the user to enter their last name and then attempts to store the value entered in the last_name array.
(bad code)
Example Language: C
char last_name[20]; printf ("Enter your last name: "); scanf ("%s", last_name);
The problem with the code above is that it does not restrict or limit the size of the name entered by the user. If the user enters "Very_very_long_last_name" which is 24 characters long, then a buffer overflow will occur since the array can only hold 20 characters total.
Example 2
The following code attempts to create a local copy of a buffer to perform some manipulations to the data.
(bad code)
Example Language: C
void manipulate_string(char * string){
char buf[24]; strcpy(buf, string); ...
}
However, the programmer does not ensure that the size of the data pointed to by string will fit in the local buffer and copies the data with the potentially dangerous strcpy() function. This may result in a buffer overflow condition if an attacker can influence the contents of the string parameter.
Example 3
The code below calls the gets() function to read in data from the command line.
(bad code)
Example Language: C
char buf[24]; printf("Please enter your name and press <Enter>\n"); gets(buf); ...
}
However, gets() is inherently unsafe, because it copies all input from STDIN to the buffer without checking size. This allows the user to provide a string that is larger than the buffer size, resulting in an overflow condition.
Example 4
In the following example, a server accepts connections from a client and processes the client request. After accepting a client connection, the program will obtain client information using the gethostbyaddr method, copy the hostname of the client that connected to a local variable and output the hostname of the client to a log file.
(bad code)
Example Language: C
...
struct hostent *clienthp; char hostname[MAX_LEN];
// create server socket, bind to server address and listen on socket ...
// accept client connections and process requests int count = 0; for (count = 0; count < MAX_CONNECTIONS; count++) {
int clientlen = sizeof(struct sockaddr_in); int clientsocket = accept(serversocket, (struct sockaddr *)&clientaddr, &clientlen);
// process client request ... close(clientsocket);
}
} close(serversocket);
...
However, the hostname of the client that connected may be longer than the allocated size for the local hostname variable. This will result in a buffer overflow when copying the client hostname to the local variable using the strcpy method.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
By replacing a valid cookie value with an extremely long string of characters, an attacker may overflow the application's buffers.
Weakness Ordinalities
Ordinality
Description
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Primary
(where the weakness exists independent of other weaknesses)
Detection
Methods
Method
Details
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 generally does not account for environmental considerations when reporting out-of-bounds memory operations. This can make it difficult for users to determine which warnings should be investigated first. For example, an analysis tool might report buffer overflows that originate from command line arguments in a program that is not expected to run with setuid or other special privileges.
Effectiveness: High
Note:Detection techniques for buffer-related errors are more mature than for most other weakness types.
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.
Manual Analysis
Manual analysis can be useful for finding this weakness, but it might not achieve desired code coverage within limited time constraints. This becomes difficult for weaknesses that must be considered for all inputs, since the attack surface can be too large.
Automated Static Analysis - Binary or Bytecode
According to SOAR, the following detection techniques may be useful:
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.
CERT C++ Secure Coding Section 07 - Characters and Strings (STR)
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).
(this CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review)
Reason
Frequent Misuse
Rationale
There are some indications that this CWE ID might be misused and selected simply because it mentions "buffer overflow" - an increasingly vague term. This CWE entry is only appropriate for "Buffer Copy" operations (not buffer reads), in which where there is no "Checking [the] Size of Input", and (by implication of the copy) writing past the end of the buffer.
Comments
If the vulnerability being analyzed involves out-of-bounds reads, then consider CWE-125 or descendants. For root cause analysis: if there is any input validation, consider children of CWE-20 such as CWE-1284. If there is a calculation error for buffer sizes, consider CWE-131 or similar.
Notes
Relationship
At the code level, stack-based and heap-based overflows do not differ significantly, so there usually is not a need to distinguish them. From the attacker perspective, they can be quite different, since different techniques are required to exploit them.
Terminology
Many issues that are now called "buffer overflows" are substantively different than the "classic" overflow, including entirely different bug types that rely on overflow exploit techniques, such as integer signedness errors, integer overflows, and format string bugs. This imprecise terminology can make it difficult to determine which variant is being reported.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
PLOVER
Unbounded Transfer ('classic overflow')
7 Pernicious Kingdoms
Buffer Overflow
CLASP
Buffer overflow
OWASP Top Ten 2004
A1
CWE More Specific
Unvalidated Input
OWASP Top Ten 2004
A5
CWE More Specific
Buffer Overflows
CERT C Secure Coding
STR31-C
Exact
Guarantee that storage for strings has sufficient space for character data and the null terminator
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 3, "Nonexecutable Stack", Page 76. 1st Edition. Addison Wesley. 2006.
[REF-62]
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 5, "Protection Mechanisms", Page 189. 1st Edition. Addison Wesley. 2006.
[REF-62]
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 8, "C String Handling", Page 388. 1st Edition. Addison Wesley. 2006.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Preprocessor (PRE) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
CWE CATEGORY: CERT C++ Secure Coding Section 02 - Declarations and Initialization (DCL)
Category ID: 870
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Declarations and Initialization (DCL) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Expressions (EXP) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Integers (INT) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
CWE CATEGORY: CERT C++ Secure Coding Section 05 - Floating Point Arithmetic (FLP)
Category ID: 873
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Floating Point Arithmetic (FLP) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
CWE CATEGORY: CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)
Category ID: 874
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Arrays and the STL (ARR) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
CWE CATEGORY: CERT C++ Secure Coding Section 07 - Characters and Strings (STR)
Category ID: 875
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Characters and Strings (STR) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Memory Management (MEM) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Input Output (FIO) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Environment (ENV) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Signals (SIG) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
CWE CATEGORY: CERT C++ Secure Coding Section 12 - Exceptions and Error Handling (ERR)
Category ID: 880
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Exceptions and Error Handling (ERR) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Object Oriented Programming (OOP) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Concurrency (CON) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
Vulnerability Mapping:PROHIBITEDThis CWE ID must not be used to map to real-world vulnerabilities
Summary
Weaknesses in this category are related to rules in the Miscellaneous (MSC) section of the CERT C++ Secure Coding Standard. Since not all rules map to specific weaknesses, this category may be incomplete.
Membership
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(this CWE ID must not be used to map to real-world vulnerabilities)
Reason:
Category
Rationale:
This entry is a Category. Using categories for mapping has been discouraged since 2019. Categories are informal organizational groupings of weaknesses that can help CWE users with data aggregation, navigation, and browsing. However, they are not weaknesses in themselves.
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:
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.
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Description
The code uses an operator for comparison when the intention was to perform an assignment.
Extended Description
In many languages, the compare statement is very close in appearance to the assignment statement; they are often confused.
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.
Impact
Details
Unexpected State
Scope: Availability, Integrity
The assignment will not take place, which should cause obvious program execution problems.
Potential Mitigations
Phase(s)
Mitigation
Testing
Many IDEs and static analysis products will detect this problem.
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" (View-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.
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
Implementation
This bug primarily originates from a typo.
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
C
(Undetermined Prevalence)
C++
(Undetermined Prevalence)
Likelihood Of Exploit
Low
Demonstrative Examples
Example 1
The following example demonstrates the weakness.
(bad code)
Example Language: Java
void called(int foo) {
foo==1; if (foo==1) System.out.println("foo\n");
} int main() {
called(2); return 0;
}
Example 2
The following C/C++ example shows a simple implementation of a stack that includes methods for adding and removing integer values from the stack. The example uses pointers to add and remove integer values to the stack array variable.
(bad code)
Example Language: C
#define SIZE 50 int *tos, *p1, stack[SIZE];
void push(int i) {
p1++; if(p1==(tos+SIZE)) {
// Print stack overflow error message and exit
} *p1 == i;
}
int pop(void) {
if(p1==tos) {
// Print stack underflow error message and exit
} p1--; return *(p1+1);
}
int main(int argc, char *argv[]) {
// initialize tos and p1 to point to the top of stack tos = stack; p1 = stack; // code to add and remove items from stack ... return 0;
}
The push method includes an expression to assign the integer value to the location in the stack pointed to by the pointer variable.
However, this expression uses the comparison operator "==" rather than the assignment operator "=". The result of using the comparison operator instead of the assignment operator causes erroneous values to be entered into the stack and can cause unexpected results.
Detection
Methods
Method
Details
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
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.
Comprehensive Categorization: Insufficient Control Flow Management
Vulnerability Mapping Notes
Usage
ALLOWED
(this CWE ID may 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
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.
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:
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Description
Sensitive memory is cleared according to the source code, but compiler optimizations leave the memory untouched when it is not read from again, aka "dead store removal."
Extended Description
This compiler optimization error occurs when:
Secret data are stored in memory.
The secret data are scrubbed from memory by overwriting its contents.
The source code is compiled using an optimizing compiler, which identifies and removes the function that overwrites the contents as a dead store because the memory is not used subsequently.
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.
Impact
Details
Read Memory; Bypass Protection Mechanism
Scope: Confidentiality, Access Control
This weakness will allow data that has not been cleared from memory to be read. If this data contains sensitive password information, then an attacker can read the password and use the information to bypass protection mechanisms.
Potential Mitigations
Phase(s)
Mitigation
Implementation
Store the sensitive data in a "volatile" memory location if available.
Build and Compilation
If possible, configure your compiler so that it does not remove dead stores.
Architecture and Design
Where possible, encrypt sensitive data that are used by a software system.
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" (View-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.
Compiler Optimization Removal or Modification of Security-critical Code
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
Implementation
Build and Compilation
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
C
(Undetermined Prevalence)
C++
(Undetermined Prevalence)
Demonstrative Examples
Example 1
The following code reads a password from the user, uses the password to connect to a back-end mainframe and then attempts to scrub the password from memory using memset().
(bad code)
Example Language: C
void GetData(char *MFAddr) {
char pwd[64]; if (GetPasswordFromUser(pwd, sizeof(pwd))) {
if (ConnectToMainframe(MFAddr, pwd)) {
// Interaction with mainframe
}
} memset(pwd, 0, sizeof(pwd));
}
The code in the example will behave correctly if it is executed verbatim, but if the code is compiled using an optimizing compiler, such as Microsoft Visual C++ .NET or GCC 3.x, then the call to memset() will be removed as a dead store because the buffer pwd is not used after its value is overwritten [18]. Because the buffer pwd contains a sensitive value, the application may be vulnerable to attack if the data are left memory resident. If attackers are able to access the correct region of memory, they may use the recovered password to gain control of the system.
It is common practice to overwrite sensitive data manipulated in memory, such as passwords or cryptographic keys, in order to prevent attackers from learning system secrets. However, with the advent of optimizing compilers, programs do not always behave as their source code alone would suggest. In the example, the compiler interprets the call to memset() as dead code because the memory being written to is not subsequently used, despite the fact that there is clearly a security motivation for the operation to occur. The problem here is that many compilers, and in fact many programming languages, do not take this and other security concerns into consideration in their efforts to improve efficiency.
Attackers typically exploit this type of vulnerability by using a core dump or runtime mechanism to access the memory used by a particular application and recover the secret information. Once an attacker has access to the secret information, it is relatively straightforward to further exploit the system and possibly compromise other resources with which the application interacts.
Detection
Methods
Method
Details
Black Box
This specific weakness is impossible to detect using black box methods. While an analyst could examine memory to see that it has not been scrubbed, an analysis of the executable would not be successful. This is because the compiler has already removed the relevant code. Only the source code shows whether the programmer intended to clear the memory or not, so this weakness is indistinguishable from others.
White Box
This weakness is only detectable using white box methods (see black box detection factor). Careful analysis is required to determine if the code is likely to be removed by the compiler.
Affected Resources
Memory
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.
CERT C++ Secure Coding Section 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).
(this CWE ID may 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
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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
7 Pernicious Kingdoms
Insecure Compiler Optimization
PLOVER
Sensitive memory uncleared by compiler optimization
OWASP Top Ten 2004
A8
CWE More Specific
Insecure Storage
CERT C Secure Coding
MSC06-C
Be aware of compiler optimization when dealing with sensitive data
CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Weakness ID: 362
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:
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Description
The product contains a concurrent code sequence that 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 operating concurrently.
Extended Description
A race condition occurs within concurrent environments, and it 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.
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.
Alternate Terms
Race Condition
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.
When a race condition makes it possible to bypass a resource cleanup routine or trigger multiple initialization routines, it may lead to resource exhaustion.
DoS: Crash, Exit, or Restart; DoS: Instability
Scope: Availability
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.
Read Files or Directories; Read Application Data
Scope: Confidentiality, Integrity
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).
Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; Bypass Protection Mechanism
Scope: Access Control
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.
Potential Mitigations
Phase(s)
Mitigation
Architecture and Design
In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
Architecture and Design
Use thread-safe capabilities such as the data access abstraction in Spring.
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).
Implementation
When using multithreading and operating on shared variables, only use thread-safe functions.
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.
Implementation
Use a mutex if available, but be sure to avoid related weaknesses such as CWE-412.
Implementation
Avoid double-checked locking (CWE-609) and other implementation errors that arise when trying to avoid the overhead of synchronization.
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.
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.
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
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" (View-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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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).
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.
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
Implementation
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).
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
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.
} 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.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
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.
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.
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].
chain: time-of-check time-of-use (TOCTOU) race condition in program allows bypass of protection mechanism that was designed to prevent symlink attacks.
chain: time-of-check time-of-use (TOCTOU) race condition in program allows bypass of protection mechanism that was designed to prevent symlink attacks.
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
Method
Details
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:
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
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).
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).
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).
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
CWE-379: Creation of Temporary File in Directory with Insecure Permissions
Weakness ID: 379
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.
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Description
The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.
Extended Description
On some operating systems, the fact that the temporary file exists may be apparent to any user with sufficient privileges to access that directory. Since the file is visible, the application that is using the temporary file could be known. If one has access to list the processes on the system, the attacker has gained information about what the user is doing at that time. By correlating this with the applications the user is running, an attacker could potentially discover what a user's actions are. From this, higher levels of security could be breached.
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.
Impact
Details
Read Application Data
Scope: Confidentiality
Since the file is visible and the application which is using the temp file could be known, the attacker has gained information about what the user is doing at that time.
Potential Mitigations
Phase(s)
Mitigation
Requirements
Many contemporary languages have functions which properly handle this condition. Older C temp file functions are especially susceptible.
Implementation
Try to store sensitive tempfiles in a directory which is not world readable -- i.e., per-user directories.
Implementation
Avoid using vulnerable temp file functions.
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" (View-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.
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
Implementation
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
(Undetermined Prevalence)
Likelihood Of Exploit
Low
Demonstrative Examples
Example 1
In the following code examples a temporary file is created and written to. After using the temporary file, the file is closed and deleted from the file system.
perror("Could not open new temporary file\n"); return (-1);
} // write data to tmp file ... // remove tmp file rmtmp();
However, within this C/C++ code the method tmpfile() is used to create and open the temp file. The tmpfile() method works the same way as the fopen() method would with read/write permission, allowing attackers to read potentially sensitive information contained in the temp file or modify the contents of the file.
(bad code)
Example Language: Java
try {
File temp = File.createTempFile("pattern", ".suffix"); temp.deleteOnExit(); BufferedWriter out = new BufferedWriter(new FileWriter(temp)); out.write("aString"); out.close();
} catch (IOException e) { }
Similarly, the createTempFile() method used in the Java code creates a temp file that may be readable and writable to all users.
Additionally both methods used above place the file into a default directory. On UNIX systems the default directory is usually "/tmp" or "/var/tmp" and on Windows systems the default directory is usually "C:\\Windows\\Temp", which may be easily accessible to attackers, possibly enabling them to read and modify the contents of the temp file.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
A Java-based application for a rapid-development framework uses File.createTempFile() to create a random temporary file with insecure default permissions.
Detection
Methods
Method
Details
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
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.
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CLASP
Guessed or visible temporary file
CERT C Secure Coding
FIO15-C
Ensure that file operations are performed in a secure directory
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 9, "Temporary Files", Page 538. 1st Edition. Addison Wesley. 2006.
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:
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Description
The product contains dead code, which can never be executed.
Extended Description
Dead code is code that can never be executed in a running program. The surrounding code makes it impossible for a section of code to ever be executed.
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.
Impact
Details
Quality Degradation
Scope: Other
Dead code that results from code that can never be executed is an indication of problems with the source code that needs to be fixed and is an indication of poor quality.
Reduce Maintainability
Scope: Other
Potential Mitigations
Phase(s)
Mitigation
Implementation
Remove dead code before deploying the application.
Testing
Use a static analysis tool to spot dead code.
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" (View-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.
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.
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.
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
Implementation
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
(Undetermined Prevalence)
Demonstrative Examples
Example 1
The condition for the second if statement is impossible to satisfy. It requires that the variables be non-null. However, on the only path where s can be assigned a non-null value, there is a return statement.
(bad code)
Example Language: C++
String s = null; if (b) {
s = "Yes"; return;
}
if (s != null) {
Dead();
}
Example 2
In the following class, two private methods call each other, but since neither one is ever invoked from anywhere else, they are both dead code.
(bad code)
Example Language: Java
public class DoubleDead {
private void doTweedledee() {
doTweedledumb();
} private void doTweedledumb() {
doTweedledee();
} public static void main(String[] args) {
System.out.println("running DoubleDead");
}
}
(In this case it is a good thing that the methods are dead: invoking either one would cause an infinite loop.)
Example 3
The field named glue is not used in the following class. The author of the class has accidentally put quotes around the field name, transforming it into a string constant.
(bad code)
Example Language: Java
public class Dead {
String glue;
public String getGlue() {
return "glue";
}
}
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
chain: incorrect "goto" in Apple SSL product bypasses certificate validation, allowing Adversary-in-the-Middle (AITM) attack (Apple "goto fail" bug). CWE-705 (Incorrect Control Flow Scoping) -> CWE-561 (Dead Code) -> CWE-295 (Improper Certificate Validation) -> CWE-393 (Return of Wrong Status Code) -> CWE-300 (Channel Accessible by Non-Endpoint).
Weakness Ordinalities
Ordinality
Description
Indirect
(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)
Detection
Methods
Method
Details
Architecture or Design Review
According to SOAR, the following detection techniques may be useful:
According to SOAR, the following detection techniques may be useful:
Highly cost effective:
Binary / Bytecode Quality Analysis
Compare binary / bytecode to application permission manifest
Effectiveness: High
Dynamic Analysis with Manual Results Interpretation
According to SOAR, the following detection techniques may be useful:
Cost effective for partial coverage:
Automated Monitored Execution
Effectiveness: SOAR Partial
Automated Static Analysis
According to SOAR, the following detection techniques may be useful:
Cost effective for partial coverage:
Permission Manifest Analysis
Effectiveness: SOAR Partial
Automated Static Analysis - Source Code
According to SOAR, the following detection techniques may be useful:
Highly cost effective:
Source Code Quality Analyzer
Cost effective for partial coverage:
Warning Flags
Source code Weakness Analyzer
Context-configured Source Code Weakness Analyzer
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
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
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.
CERT C++ Secure Coding Section 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).
(this CWE ID may 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.
CWE-390: Detection of Error Condition Without Action
Weakness ID: 390
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:
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Description
The product detects a specific error, but takes no actions to handle the error.
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.
Impact
Details
Varies by Context; Unexpected State; Alter Execution Logic
Scope: Integrity, Other
An attacker could utilize an ignored error condition to place the system in an unexpected state that could lead to the execution of unintended logic and could cause other unintended behavior.
Potential Mitigations
Phase(s)
Mitigation
Implementation
Properly handle each exception. This is the recommended solution. Ensure that all exceptions are handled in such a way that you can be sure of the state of your system at any given moment.
Implementation
If a function returns an error, it is important to either fix the problem and try again, alert the user that an error has happened and let the program continue, or alert the user and close and cleanup the program.
Testing
Subject the product to extensive testing to discover some of the possible instances of where/how errors or return values are not handled. Consider testing techniques such as ad hoc, equivalence partitioning, robustness and fault tolerance, mutation, and fuzzing.
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" (View-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.
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.
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.
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
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
(Undetermined Prevalence)
Likelihood Of Exploit
Medium
Demonstrative Examples
Example 1
The following example attempts to allocate memory for a character. After the call to malloc, an if statement is used to check whether the malloc function failed.
(bad code)
Example Language: C
foo=malloc(sizeof(char)); //the next line checks to see if malloc failed if (foo==NULL) {
//We do nothing so we just ignore the error.
}
The conditional successfully detects a NULL return value from malloc indicating a failure, however it does not do anything to handle the problem. Unhandled errors may have unexpected results and may cause the program to crash or terminate.
Instead, the if block should contain statements that either attempt to fix the problem or notify the user that an error has occurred and continue processing or perform some cleanup and gracefully terminate the program. The following example notifies the user that the malloc function did not allocate the required memory resources and returns an error code.
(good code)
Example Language: C
foo=malloc(sizeof(char)); //the next line checks to see if malloc failed if (foo==NULL) {
printf("Malloc failed to allocate memory resources"); return -1;
}
Example 2
In the following C++ example the method readFile() will read the file whose name is provided in the input parameter and will return the contents of the file in char string. The method calls open() and read() may result in errors if the file does not exist or does not contain any data to read. These errors will be thrown when the is_open() method and good() method indicate errors opening or reading the file. However, these errors are not handled within the catch statement. Catch statements that do not perform any processing will have unexpected results. In this case an empty char string will be returned, and the file will not be properly closed.
(bad code)
Example Language: C++
char* readfile (char *filename) {
try {
// open input file ifstream infile; infile.open(filename);
if (!infile.is_open()) {
throw "Unable to open file " + filename;
}
// get length of file infile.seekg (0, ios::end); int length = infile.tellg(); infile.seekg (0, ios::beg);
// allocate memory char *buffer = new char [length];
// read data from file infile.read (buffer,length);
if (!infile.good()) {
throw "Unable to read from file " + filename;
}
infile.close();
return buffer;
} catch (...) {
/* bug: insert code to handle this later */
}
}
The catch statement should contain statements that either attempt to fix the problem or notify the user that an error has occurred and continue processing or perform some cleanup and gracefully terminate the program. The following C++ example contains two catch statements. The first of these will catch a specific error thrown within the try block, and the second catch statement will catch all other errors from within the catch block. Both catch statements will notify the user that an error has occurred, close the file, and rethrow to the block that called the readFile() method for further handling or possible termination of the program.
(good code)
Example Language: C++
char* readFile (char *filename) {
try {
// open input file ifstream infile; infile.open(filename);
if (!infile.is_open()) {
throw "Unable to open file " + filename;
}
// get length of file infile.seekg (0, ios::end); int length = infile.tellg(); infile.seekg (0, ios::beg);
// allocate memory char *buffer = new char [length];
// read data from file infile.read (buffer,length);
printf("Error occurred trying to read from file \n"); infile.close(); throw;
}
}
Example 3
In the following Java example the method readFile will read the file whose name is provided in the input parameter and will return the contents of the file in a String object. The constructor of the FileReader object and the read method call may throw exceptions and therefore must be within a try/catch block. While the catch statement in this example will catch thrown exceptions in order for the method to compile, no processing is performed to handle the thrown exceptions. Catch statements that do not perform any processing will have unexpected results. In this case, this will result in the return of a null String.
(bad code)
Example Language: Java
public String readFile(String filename) {
String retString = null; try {
// initialize File and FileReader objects File file = new File(filename); FileReader fr = new FileReader(file);
// initialize character buffer long fLen = file.length(); char[] cBuf = new char[(int) fLen];
// read data from file int iRead = fr.read(cBuf, 0, (int) fLen);
// close file fr.close();
retString = new String(cBuf);
} catch (Exception ex) {
/* do nothing, but catch so it'll compile... */
} return retString;
}
The catch statement should contain statements that either attempt to fix the problem, notify the user that an exception has been raised and continue processing, or perform some cleanup and gracefully terminate the program. The following Java example contains three catch statements. The first of these will catch the FileNotFoundException that may be thrown by the FileReader constructor called within the try/catch block. The second catch statement will catch the IOException that may be thrown by the read method called within the try/catch block. The third catch statement will catch all other exceptions thrown within the try block. For all catch statements the user is notified that the exception has been thrown and the exception is rethrown to the block that called the readFile() method for further processing or possible termination of the program. Note that with Java it is usually good practice to use the getMessage() method of the exception class to provide more information to the user about the exception raised.
(good code)
Example Language: Java
public String readFile(String filename) throws FileNotFoundException, IOException, Exception {
String retString = null; try {
// initialize File and FileReader objects File file = new File(filename); FileReader fr = new FileReader(file);
// initialize character buffer long fLen = file.length(); char [] cBuf = new char[(int) fLen];
// read data from file int iRead = fr.read(cBuf, 0, (int) fLen);
// close file fr.close();
retString = new String(cBuf);
} catch (FileNotFoundException ex) {
System.err.println ("Error: FileNotFoundException opening the input file: " + filename ); System.err.println ("" + ex.getMessage() ); throw new FileNotFoundException(ex.getMessage());
} catch (IOException ex) {
System.err.println("Error: IOException reading the input file.\n" + ex.getMessage() ); throw new IOException(ex);
} catch (Exception ex) {
System.err.println("Error: Exception reading the input file.\n" + ex.getMessage() ); throw new Exception(ex);
} return retString;
}
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
A GPU data center manager detects an error due to a malformed request but does not act on it, leading to memory corruption.
Detection
Methods
Method
Details
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
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.
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).
Comprehensive Categorization: Improper Check or Handling of Exceptional Conditions
Vulnerability Mapping Notes
Usage
ALLOWED
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CLASP
Improper error handling
The CERT Oracle Secure Coding Standard for Java (2011)
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.
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.
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Description
The product divides a value by zero.
Extended Description
This weakness typically occurs when an unexpected value is provided to the product, or if an error occurs that is not properly detected. It frequently occurs in calculations involving physical dimensions such as size, length, width, and height.
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.
Impact
Details
DoS: Crash, Exit, or Restart
Scope: Availability
A Divide by Zero results in a crash.
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" (View-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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-1003)
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.
Relevant to the view "CISQ Quality Measures (2020)" (View-1305)
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.
Relevant to the view "CISQ Data Protection Measures" (View-1340)
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.
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
Implementation
Likelihood Of Exploit
Medium
Demonstrative Examples
Example 1
The following Java example contains a function to compute an average but does not validate that the input value used as the denominator is not zero. This will create an exception for attempting to divide by zero. If this error is not handled by Java exception handling, unexpected results can occur.
(bad code)
Example Language: Java
public int computeAverageResponseTime (int totalTime, int numRequests) {
return totalTime / numRequests;
}
By validating the input value used as the denominator the following code will ensure that a divide by zero error will not cause unexpected results. The following Java code example will validate the input value, output an error message, and throw an exception.
(good code)
Example Language: Java
public int computeAverageResponseTime (int totalTime, int numRequests) throws ArithmeticException {
if (numRequests == 0) {
System.out.println("Division by zero attempted!"); throw ArithmeticException;
} return totalTime / numRequests;
}
Example 2
The following C/C++ example contains a function that divides two numeric values without verifying that the input value used as the denominator is not zero. This will create an error for attempting to divide by zero, if this error is not caught by the error handling capabilities of the language, unexpected results can occur.
(bad code)
Example Language: C
double divide(double x, double y){
return x/y;
}
By validating the input value used as the denominator the following code will ensure that a divide by zero error will not cause unexpected results. If the method is called and a zero is passed as the second argument a DivideByZero error will be thrown and should be caught by the calling block with an output message indicating the error.
(good code)
Example Language: C
const int DivideByZero = 10; double divide(double x, double y){
The following C# example contains a function that divides two numeric values without verifying that the input value used as the denominator is not zero. This will create an error for attempting to divide by zero, if this error is not caught by the error handling capabilities of the language, unexpected results can occur.
(bad code)
Example Language: C#
int Division(int x, int y){
return (x / y);
}
The method can be modified to raise, catch and handle the DivideByZeroException if the input value used as the denominator is zero.
(good code)
Example Language: C#
int SafeDivision(int x, int y){
try{
return (x / y);
} catch (System.DivideByZeroException dbz){
System.Console.WriteLine("Division by zero attempted!"); return 0;
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
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
Fuzzing
Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.
Effectiveness: High
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.
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).
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
OWASP Top Ten 2004
A9
CWE More Specific
Denial of Service
CERT C Secure Coding
FLP03-C
Detect and handle floating point errors
CERT C Secure Coding
INT33-C
Exact
Ensure that division and remainder operations do not result in divide-by-zero errors
The CERT Oracle Secure Coding Standard for Java (2011)
NUM02-J
Ensure that division and modulo operations do not result in divide-by-zero errors
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:
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Description
The product calls free() twice on the same memory address.
Alternate Terms
Double-free
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.
Impact
Details
Modify Memory; Execute Unauthorized Code or Commands
Scope: Integrity, Confidentiality, Availability
When a program calls free() twice with the same argument, the program's memory management data structures may become corrupted, potentially leading to the reading or modification of unexpected memory addresses. This corruption can cause the program to crash or, in some circumstances, cause two later calls to malloc() to return the same pointer. If malloc() returns the same value twice and the program later gives the attacker control over the data that is written into this doubly-allocated memory, the program becomes vulnerable to a buffer overflow attack.
Doubly freeing memory may result in a write-what-where condition, allowing an attacker to execute arbitrary code.
Potential Mitigations
Phase(s)
Mitigation
Architecture and Design
Choose a language that provides automatic memory management.
Implementation
Ensure that each allocation is freed only once. After freeing a chunk, set the pointer to NULL to ensure the pointer cannot be freed again. In complicated error conditions, be sure that clean-up routines respect the state of allocation properly. If the language is object oriented, ensure that object destructors delete each chunk of memory only once.
Implementation
Use a static analysis tool to find double free instances.
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" (View-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.
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.
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.
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.
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.
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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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.
Operation on a Resource after Expiration or Release
Relevant to the view "CISQ Quality Measures (2020)" (View-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.
Operation on a Resource after Expiration or Release
Relevant to the view "CISQ Data Protection Measures" (View-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.
Operation on a Resource after Expiration or Release
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
Implementation
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
C
(Undetermined Prevalence)
C++
(Undetermined Prevalence)
Likelihood Of Exploit
High
Demonstrative Examples
Example 1
The following code shows a simple example of a double free vulnerability.
(bad code)
Example Language: C
char* ptr = (char*)malloc (SIZE);
...
if (abrt) {
free(ptr);
}
...
free(ptr);
Double free vulnerabilities have two common (and sometimes overlapping) causes:
Error conditions and other exceptional circumstances
Confusion over which part of the program is responsible for freeing the memory
Although some double free vulnerabilities are not much more complicated than this example, most are spread out across hundreds of lines of code or even different files. Programmers seem particularly susceptible to freeing global variables more than once.
Example 2
While contrived, this code should be exploitable on Linux distributions that do not ship with heap-chunk check summing turned on.
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.
Effectiveness: High
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
Affected Resources
Memory
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.
(this CWE ID may 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
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 is usually resultant from another weakness, such as an unhandled error or race condition between threads. It could also be primary to weaknesses such as buffer overflows.
Theoretical
It could be argued that Double Free would be most appropriately located as a child of "Use after Free", but "Use" and "Release" are considered to be distinct operations within vulnerability theory, therefore this is more accurately "Release of a Resource after Expiration or Release", which doesn't exist yet.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
PLOVER
DFREE - Double-Free Vulnerability
7 Pernicious Kingdoms
Double Free
CLASP
Doubly freeing memory
CERT C Secure Coding
MEM00-C
Allocate and free memory in the same module, at the same level of abstraction
CERT C Secure Coding
MEM01-C
Store a new value in pointers immediately after free()
CERT C Secure Coding
MEM30-C
CWE More Specific
Do not access freed memory
CERT C Secure Coding
MEM31-C
Free dynamically allocated memory exactly once
Software Fault Patterns
SFP12
Faulty Memory Release
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.
[REF-62]
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 7, "Double Frees", Page 379. 1st Edition. Addison Wesley. 2006.
CWE-462: Duplicate Key in Associative List (Alist)
Weakness ID: 462
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:
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Description
Duplicate keys in associative lists can lead to non-unique keys being mistaken for an error.
Extended Description
A duplicate key entry -- if the alist is designed properly -- could be used as a constant time replace function. However, duplicate key entries could be inserted by mistake. Because of this ambiguity, duplicate key entries in an association list are not recommended and should not be allowed.
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.
Impact
Details
Quality Degradation; Varies by Context
Scope: Other
Potential Mitigations
Phase(s)
Mitigation
Architecture and Design
Use a hash table instead of an alist.
Architecture and Design
Use an alist which checks the uniqueness of hash keys with each entry before inserting the entry.
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" (View-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.
Use of Multiple Resources with Duplicate Identifier
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
Implementation
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
C
(Undetermined Prevalence)
C++
(Undetermined Prevalence)
Java
(Undetermined Prevalence)
C#
(Undetermined Prevalence)
Likelihood Of Exploit
Low
Demonstrative Examples
Example 1
The following code adds data to a list and then attempts to sort the data.
(bad code)
Example Language: Python
alist = [] while (foo()): #now assume there is a string data with a key basename
queue.append(basename,data) queue.sort()
Since basename is not necessarily unique, this may not sort how one would like it to be.
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.
(this CWE ID may 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
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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CLASP
Duplicate key in associative list (alist)
CERT C Secure Coding
ENV02-C
Beware of multiple environment variables with the same effective name
CWE-528: Exposure of Core Dump File to an Unauthorized Control Sphere
Weakness ID: 528
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:
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.
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Description
The product generates a core dump file in a directory, archive, or other resource that is stored, transferred, or otherwise made accessible to unauthorized actors.
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.
Impact
Details
Read Application Data; Read Files or Directories
Scope: Confidentiality
Potential Mitigations
Phase(s)
Mitigation
System Configuration
Protect the core dump files from unauthorized access.
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" (View-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.
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
Operation
OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Detection
Methods
Method
Details
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
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.
(this CWE ID may 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
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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CERT C Secure Coding
MEM06-C
Ensure that sensitive data is not written out to disk
CWE-488: Exposure of Data Element to Wrong Session
Weakness ID: 488
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:
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Description
The product does not sufficiently enforce boundaries between the states of different sessions, causing data to be provided to, or used by, the wrong session.
Extended Description
Data can "bleed" from one session to another through member variables of singleton objects, such as Servlets, and objects from a shared pool.
In the case of Servlets, developers sometimes do not understand that, unless a Servlet implements the SingleThreadModel interface, the Servlet is a singleton; there is only one instance of the Servlet, and that single instance is used and re-used to handle multiple requests that are processed simultaneously by different threads. A common result is that developers use Servlet member fields in such a way that one user may inadvertently see another user's data. In other words, storing user data in Servlet member fields introduces a data access race condition.
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.
Impact
Details
Read Application Data
Scope: Confidentiality
Potential Mitigations
Phase(s)
Mitigation
Architecture and Design
Protect the application's sessions from information leakage. Make sure that a session's data is not used or visible by other sessions.
Testing
Use a static analysis tool to scan the code for information leakage vulnerabilities (e.g. Singleton Member Field).
Architecture and Design
In a multithreading environment, storing user data in Servlet member fields introduces a data access race condition. Do not use member fields to store information in the Servlet.
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" (View-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.
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.
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
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
(Undetermined Prevalence)
Demonstrative Examples
Example 1
The following Servlet stores the value of a request parameter in a member field and then later echoes the parameter value to the response output stream.
name = req.getParameter("name"); ... out.println(name + ", thanks for visiting!");
}
}
While this code will work perfectly in a single-user environment, if two users access the Servlet at approximately the same time, it is possible for the two request handler threads to interleave in the following way: Thread 1: assign "Dick" to name Thread 2: assign "Jane" to name Thread 1: print "Jane, thanks for visiting!" Thread 2: print "Jane, thanks for visiting!" Thereby showing the first user the second user's name.
Detection
Methods
Method
Details
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
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.
(this CWE ID may 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.
CWE-403: Exposure of File Descriptor to Unintended Control Sphere ('File Descriptor Leak')
Weakness ID: 403
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.
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Description
A process does not close sensitive file descriptors before invoking a child process, which allows the child to perform unauthorized I/O operations using those descriptors.
Extended Description
When a new process is forked or executed, the child process inherits any open file descriptors. When the child process has fewer privileges than the parent process, this might introduce a vulnerability if the child process can access the file descriptor but does not have the privileges to access the associated file.
Alternate Terms
File descriptor leak
While this issue is frequently called a file descriptor leak, the "leak" term is often used in two different ways - exposure of a resource, or consumption of a resource. Use of this term could cause confusion.
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.
Impact
Details
Read Application Data; Modify Application Data
Scope: Confidentiality, Integrity
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" (View-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.
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
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
C
(Undetermined Prevalence)
Class: Not Language-Specific
(Undetermined Prevalence)
Operating Systems
Class: Unix
(Undetermined Prevalence)
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Module opens a file for reading twice, allowing attackers to read files.
Affected Resources
System Process
File or Directory
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.
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
PLOVER
UNIX file descriptor leak
CERT C Secure Coding
FIO42-C
Ensure files are properly closed when they are no longer needed
CWE-497: Exposure of Sensitive System Information to an Unauthorized Control Sphere
Weakness ID: 497
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:
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Description
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.
Extended Description
Network-based products, such as web applications, often run on top of an operating system or similar environment. When the product communicates with outside parties, details about the underlying system are expected to remain hidden, such as path names for data files, other OS users, installed packages, the application environment, etc. This system information may be provided by the product itself, or buried within diagnostic or debugging messages. Debugging information helps an adversary learn about the system and form an attack plan.
An information exposure occurs when system data or debugging information leaves the program through an output stream or logging function that makes it accessible to unauthorized parties. Using other weaknesses, an attacker could cause errors to occur; the response to these errors can reveal detailed system information, along with other impacts. An attacker can use messages that reveal technologies, operating systems, and product versions to tune the attack against known vulnerabilities in these technologies. A product may use diagnostic methods that provide significant implementation details such as stack traces as part of its error handling mechanism.
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.
Impact
Details
Read Application Data
Scope: Confidentiality
Potential Mitigations
Phase(s)
Mitigation
Architecture and Design; Implementation
Production applications should never use methods that generate internal details such as stack traces and error messages unless that information is directly committed to a log that is not viewable by the end user. All error message text should be HTML entity encoded before being written to the log file to protect against potential cross-site scripting attacks against the viewer of the logs
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" (View-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.
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.
Invocation of Process Using Visible 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.
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.
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
Implementation
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
(Undetermined Prevalence)
Demonstrative Examples
Example 1
The following code prints the path environment variable to the standard error stream:
This code prints all of the running processes belonging to the current user.
(bad code)
Example Language: PHP
//assume getCurrentUser() returns a username that is guaranteed to be alphanumeric (avoiding CWE-78) $userName = getCurrentUser(); $command = 'ps aux | grep ' . $userName; system($command);
If invoked by an unauthorized web user, it is providing a web page of potentially sensitive information on the underlying system, such as command-line arguments (CWE-497). This program is also potentially vulnerable to a PATH based attack (CWE-426), as an attacker may be able to create malicious versions of the ps or grep commands. While the program does not explicitly raise privileges to run the system commands, the PHP interpreter may by default be running with higher privileges than users.
Example 3
The following code prints an exception to the standard error stream:
(bad code)
Example Language: Java
try {
...
} catch (Exception e) {
e.printStackTrace();
}
(bad code)
Example Language: Java
try {
...
} catch (Exception e) {
Console.Writeline(e);
}
Depending upon the system configuration, this information can be dumped to a console, written to a log file, or exposed to a remote user. In some cases the error message tells the attacker precisely what sort of an attack the system will be vulnerable to. For example, a database error message can reveal that the application is vulnerable to a SQL injection attack. Other error messages can reveal more oblique clues about the system. In the example above, the search path could imply information about the type of operating system, the applications installed on the system, and the amount of care that the administrators have put into configuring the program.
Example 4
The following code constructs a database connection string, uses it to create a new connection to the database, and prints it to the console.
Depending on the system configuration, this information can be dumped to a console, written to a log file, or exposed to a remote user. In some cases the error message tells the attacker precisely what sort of an attack the system is vulnerable to. For example, a database error message can reveal that the application is vulnerable to a SQL injection attack. Other error messages can reveal more oblique clues about the system. In the example above, the search path could imply information about the type of operating system, the applications installed on the system, and the amount of care that the administrators have put into configuring the program.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Code analysis product passes access tokens as a command-line parameter or through an environment variable, making them visible to other processes via the ps command.
Detection
Methods
Method
Details
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
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.
Comprehensive Categorization: Sensitive Information Exposure
Vulnerability Mapping Notes
Usage
ALLOWED
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
7 Pernicious Kingdoms
System Information Leak
The CERT Oracle Secure Coding Standard for Java (2011)
ERR01-J
Do not allow exceptions to expose sensitive information
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.
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Description
The product contains an expression that will always evaluate to false.
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.
Impact
Details
Quality Degradation; Varies by Context
Scope: Other
Potential Mitigations
Phase(s)
Mitigation
Testing
Use Static Analysis tools to spot such conditions.
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" (View-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.
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.
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
Implementation
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
(Undetermined Prevalence)
Demonstrative Examples
Example 1
In the following Java example the updateUserAccountOrder() method used within an e-business product ordering/inventory application will validate the product number that was ordered and the user account number. If they are valid, the method will update the product inventory, the user account, and the user order appropriately.
(bad code)
Example Language: Java
public void updateUserAccountOrder(String productNumber, String accountNumber) {
However, the method never sets the isValidAccount variable after initializing it to false so the isValidProduct is mistakenly used twice. The result is that the expression "isValidProduct && isValidAccount" will always evaluate to false, so the updateAccountOrder() method will never be invoked. This will create serious problems with the product ordering application since the user account and inventory databases will be updated but the order will not be updated.
This can be easily corrected by updating the appropriate variable.
In the following example, the hasReadWriteAccess method uses bit masks and bit operators to determine if a user has read and write privileges for a particular process. The variable mask is defined as a bit mask from the BIT_READ and BIT_WRITE constants that have been defined. The variable mask is used within the predicate of the hasReadWriteAccess method to determine if the userMask input parameter has the read and write bits set.
unsigned int mask = BIT_READ & BIT_WRITE; /* intended to use "|" */
// using "&", mask = 00000000 // using "|", mask = 00010001
// determine if user has read and write access int hasReadWriteAccess(unsigned int userMask) {
// if the userMask has read and write bits set // then return 1 (true) if (userMask & mask) {
return 1;
}
// otherwise return 0 (false) return 0;
}
However the bit operator used to initialize the mask variable is the AND operator rather than the intended OR operator (CWE-480), this resulted in the variable mask being set to 0. As a result, the if statement will always evaluate to false and never get executed.
The use of bit masks, bit operators and bitwise operations on variables can be difficult. If possible, try to use frameworks or libraries that provide appropriate functionality and abstract the implementation.
Example 3
In the following example, the updateInventory method used within an e-business inventory application will update the inventory for a particular product. This method includes an if statement with an expression that will always evaluate to false. This is a common practice in C/C++ to introduce debugging statements quickly by simply changing the expression to evaluate to true and then removing those debugging statements by changing expression to evaluate to false. This is also a common practice for disabling features no longer needed.
(bad code)
Example Language: C
int updateInventory(char* productNumber, int numberOfItems) {
int initCount = getProductCount(productNumber);
int updatedCount = initCount + numberOfItems;
int updated = updateProductCount(updatedCount);
// if statement for debugging purposes only if (1 == 0) {
printf("product %s initially has %d items in inventory \n", productName, initCount); printf("adding %d items to inventory for %s \n", numberOfItems, productName);
if (updated == 0) {
printf("Inventory updated for product %s to %d items \n", productName, updatedCount);
}
else {
printf("Inventory not updated for product: %s \n", productName);
}
}
return updated;
}
Using this practice for introducing debugging statements or disabling features creates dead code that can cause problems during code maintenance and potentially introduce vulnerabilities. To avoid using expressions that evaluate to false for debugging purposes a logging API or debugging API should be used for the output of debugging messages.
Detection
Methods
Method
Details
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
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.
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CERT C Secure Coding
MSC00-C
Compile cleanly at high warning levels
Software Fault Patterns
SFP1
Glitch in computation
Content
History
Submissions
Submission Date
Submitter
Organization
2006-12-15
(CWE Draft 5, 2006-12-15)
CWE Community
Submitted by members of the CWE community to extend early CWE versions
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.
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Description
The product contains an expression that will always evaluate to true.
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.
Impact
Details
Quality Degradation; Varies by Context
Scope: Other
Potential Mitigations
Phase(s)
Mitigation
Testing
Use Static Analysis tools to spot such conditions.
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" (View-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.
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.
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
Implementation
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
(Undetermined Prevalence)
Demonstrative Examples
Example 1
In the following Java example the updateInventory() method used within an e-business product ordering/inventory application will check if the input product number is in the store or in the warehouse. If the product is found, the method will update the store or warehouse database as well as the aggregate product database. If the product is not found, the method intends to do some special processing without updating any database.
(bad code)
Example Language: Java
public void updateInventory(String productNumber) {
/* Warn customer about delay before order processing */ ...
}
}
However, the method never sets the isDelayed variable and instead will always update the isProductAvailable variable to true. The result is that the predicate testing the isProductAvailable boolean will always evaluate to true and therefore always update the product database. Further, since the isDelayed variable is initialized to false and never changed, the expression always evaluates to false and the customer will never be warned of a delay on their product.
Detection
Methods
Method
Details
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
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.
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CERT C Secure Coding
MSC00-C
Compile cleanly at high warning levels
Software Fault Patterns
SFP1
Glitch in computation
Content
History
Submissions
Submission Date
Submitter
Organization
2006-12-15
(CWE Draft 5, 2006-12-15)
CWE Community
Submitted by members of the CWE community to extend early CWE versions
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.
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Description
The product allows user input to control or influence paths or file names that are used in filesystem operations.
Extended Description
This could allow an attacker to access or modify system files or other files that are critical to the application.
Path manipulation errors occur when the following two conditions are met:
1. An attacker can specify a path used in an operation on the filesystem.
2. By specifying the resource, the attacker gains a capability that would not otherwise be permitted.
For example, the program may give the attacker the ability to overwrite the specified file or run with a configuration controlled by the attacker.
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.
Impact
Details
Read Files or Directories; Modify Files or Directories
Scope: Integrity, Confidentiality
The application can operate on unexpected files. Confidentiality is violated when the targeted filename is not directly readable by the attacker.
Modify Files or Directories; Execute Unauthorized Code or Commands
Scope: Integrity, Confidentiality, Availability
The application can operate on unexpected files. This may violate integrity if the filename is written to, or if the filename is for a program or other form of executable code.
DoS: Crash, Exit, or Restart; DoS: Resource Consumption (Other)
Scope: Availability
The application can operate on unexpected files. Availability can be violated if the attacker specifies an unexpected file that the application modifies. Availability can also be affected if the attacker specifies a filename for a large file, or points to a special device or a file that does not have the format that the application expects.
Potential Mitigations
Phase(s)
Mitigation
Architecture and Design
When the set of filenames is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames, and reject all other inputs. For example, ID 1 could map to "inbox.txt" and ID 2 could map to "profile.txt". Features such as the ESAPI AccessReferenceMap provide this capability.
Architecture and Design; Operation
Run your code in a "jail" or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict all access to files within a particular directory.
Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection.
This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise.
Be careful to avoid CWE-243 and other weaknesses related to jails.
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.
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.
When validating filenames, use stringent allowlists that limit the character set to be used. If feasible, only allow a single "." character in the filename to avoid weaknesses such as CWE-23, and exclude directory separators such as "/" to avoid CWE-36. Use a list of allowable file extensions, which will help to avoid CWE-434.
Do not rely exclusively on a filtering mechanism that removes potentially dangerous characters. This is equivalent to a denylist, which may be incomplete (CWE-184). For example, filtering "/" is insufficient protection if the filesystem also supports the use of "\" as a directory separator. Another possible error could occur when the filtering is applied in a way that still produces dangerous data (CWE-182). For example, if "../" sequences are removed from the ".../...//" string in a sequential fashion, two instances of "../" would be removed from the original string, but the remaining characters would still form the "../" string.
Effectiveness: High
Implementation
Use a built-in path canonicalization function (such as realpath() in C) that produces the canonical version of the pathname, which effectively removes ".." sequences and symbolic links (CWE-23, CWE-59).
Installation; Operation
Use OS-level permissions and run as a low-privileged user to limit the scope of any successful attack.
Operation; Implementation
If you are using PHP, configure your application so that it does not use register_globals. During implementation, develop your 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.
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.
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" (View-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.
Externally Controlled Reference to a Resource in Another 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.
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.
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.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
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.
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.
Improper Link Resolution Before File Access ('Link Following')
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.
Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
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.
Relevant to the view "Seven Pernicious Kingdoms" (View-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.
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
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
(Undetermined Prevalence)
Operating Systems
Class: Unix
(Often Prevalent)
Class: Windows
(Often Prevalent)
Class: macOS
(Often Prevalent)
Likelihood Of Exploit
High
Demonstrative Examples
Example 1
The following code uses input from an HTTP request to create a file name. The programmer has not considered the possibility that an attacker could provide a file name such as "../../tomcat/conf/server.xml", which causes the application to delete one of its own configuration files (CWE-22).
The following code uses input from a configuration file to determine which file to open and echo back to the user. If the program runs with privileges and malicious users can change the configuration file, they can use the program to read any file on the system that ends with the extension .txt.
(bad code)
Example Language: Java
fis = new FileInputStream(cfg.getProperty("sub")+".txt"); amt = fis.read(arr); out.println(arr);
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Chain: a learning management tool debugger uses external input to locate previous session logs (CWE-73) and does not properly validate the given path (CWE-20), allowing for filesystem path traversal using "../" sequences (CWE-24)
Chain: external control of user's target language enables remote file inclusion.
Weakness Ordinalities
Ordinality
Description
Primary
(where the weakness exists independent of other weaknesses)
Detection
Methods
Method
Details
Automated Static Analysis
The external control or influence of filenames can often be detected using automated static analysis that models data flow within the product.
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.
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.
(this CWE ID may 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
The external control of filenames can be the primary link in chains with other file-related weaknesses, as seen in the CanPrecede relationships. This is because software systems use files for many different purposes: to execute programs, load code libraries, to store application data, to store configuration settings, record temporary data, act as signals or semaphores to other processes, etc.
However, those weaknesses do not always require external control. For example, link-following weaknesses (CWE-59) often involve pathnames that are not controllable by the attacker at all.
The external control can be resultant from other issues. For example, in PHP applications, the register_globals setting can allow an attacker to modify variables that the programmer thought were immutable, enabling file inclusion (CWE-98) and path traversal (CWE-22). Operating with excessive privileges (CWE-250) might allow an attacker to specify an input filename that is not directly readable by the attacker, but is accessible to the privileged program. A buffer overflow (CWE-119) might give an attacker control over nearby memory locations that are related to pathnames, but were not directly modifiable by the attacker.
Maintenance
CWE-114 is a Class, but it is listed a child of CWE-73 in view 1000. This suggests some abstraction problems that should be resolved in future versions.
CWE-552: Files or Directories Accessible to External Parties
Weakness ID: 552
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.
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Description
The product makes files or directories accessible to unauthorized actors, even though they should not be.
Extended Description
Web servers, FTP servers, and similar servers may store a set of files underneath a "root" directory that is accessible to the server's users. Applications may store sensitive files underneath this root without also using access control to limit which users may request those files, if any. Alternately, an application might package multiple files or directories into an archive file (e.g., ZIP or tar), but the application might not exclude sensitive files that are underneath those directories.
In cloud technologies and containers, this weakness might present itself in the form of misconfigured storage accounts that can be read or written by a public or anonymous user.
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.
Impact
Details
Read Files or Directories; Modify Files or Directories
Scope: Confidentiality, Integrity
Potential Mitigations
Phase(s)
Mitigation
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
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" (View-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.
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.
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.
Storage of File with Sensitive Data Under Web Root
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.
Storage of File With Sensitive Data Under FTP Root
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.
Exposure of Version-Control Repository to an Unauthorized Control Sphere
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.
Exposure of Core Dump File to an Unauthorized Control Sphere
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.
Exposure of Access Control List Files to an Unauthorized Control Sphere
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.
Exposure of Backup File to an Unauthorized Control Sphere
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.
Use of Persistent Cookies 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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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.
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
Implementation
OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
Operation
OMISSION: This weakness is caused by missing a security tactic during the architecture and design phase.
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
(Undetermined Prevalence)
Technologies
Class: Not Technology-Specific
(Undetermined Prevalence)
Class: Cloud Computing
(Often Prevalent)
Demonstrative Examples
Example 1
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 2
The following Google Cloud Storage command gets the settings for a storage account named 'BUCKET_NAME':
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
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
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
Affected Resources
File or Directory
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.
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
OWASP Top Ten 2004
A10
CWE More Specific
Insecure Configuration Management
CERT C Secure Coding
FIO15-C
Ensure that file operations are performed in a secure directory
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)
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:
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Description
The product calls free() on a pointer to memory that was not allocated using associated heap allocation functions such as malloc(), calloc(), or realloc().
Extended Description
When free() is called on an invalid pointer, the program's memory management data structures may become corrupted. This corruption can cause the program to crash or, in some circumstances, an attacker may be able to cause free() to operate on controllable memory locations to modify critical program variables or execute code.
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.
Impact
Details
Execute Unauthorized Code or Commands; Modify Memory
Scope: Integrity, Confidentiality, Availability
There is the potential for arbitrary code execution with privileges of the vulnerable program via a "write, what where" primitive. If pointers to memory which hold user information are freed, a malicious user will be able to write 4 bytes anywhere in memory.
Potential Mitigations
Phase(s)
Mitigation
Implementation
Only free pointers that you have called malloc on previously. This is the recommended solution. Keep track of which pointers point at the beginning of valid chunks and free them only once.
Implementation
Before freeing a pointer, the programmer should make sure that the pointer was previously allocated on the heap and that the memory belongs to the programmer. Freeing an unallocated pointer will cause undefined behavior in the program.
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, glibc in Linux provides protection against free of invalid pointers.
Architecture and Design
Use a language that provides abstractions for memory allocation and deallocation.
Testing
Use a tool that dynamically detects memory management problems, such as valgrind.
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" (View-1000)
Nature
Type
ID
Name
ChildOf
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.
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.
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
Implementation
Demonstrative Examples
Example 1
In this example, an array of record_t structs, bar, is allocated automatically on the stack as a local variable and the programmer attempts to call free() on the array. The consequences will vary based on the implementation of free(), but it will not succeed in deallocating the memory.
(bad code)
Example Language: C
void foo(){
record_t bar[MAX_SIZE];
/* do something interesting with bar */
... free(bar);
}
This example shows the array allocated globally, as part of the data segment of memory and the programmer attempts to call free() on the array.
(bad code)
Example Language: C
record_t bar[MAX_SIZE]; //Global var void foo(){
/* do something interesting with bar */ ... free(bar);
}
Instead, if the programmer wanted to dynamically manage the memory, malloc() or calloc() should have been used.
Additionally, global variables could be passed to free() when they are pointers to dynamically allocated memory.
(good code)
Example Language: C
record_t *bar; //Global var void foo(){
bar = (record_t*)malloc(MAX_SIZE*sizeof(record_t));
/* do something interesting with bar */
... free(bar);
}
Detection
Methods
Method
Details
Fuzzing
Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.
Effectiveness: High
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
Affected Resources
Memory
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.
(this CWE ID may 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
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
Other
In C++, if the new operator was used to allocate the memory, it may be allocated with the malloc(), calloc() or realloc() family of functions in the implementation. Someone aware of this behavior might choose to map this problem to CWE-590 or to its parent, CWE-762, depending on their perspective.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CERT C Secure Coding
MEM34-C
Exact
Only free memory allocated dynamically
CERT C Secure Coding
WIN30-C
Imprecise
Properly pair allocation and deallocation functions
CWE-686: Function Call With Incorrect Argument Type
Weakness ID: 686
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:
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.
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Description
The product calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses.
Extended Description
This weakness is most likely to occur in loosely typed languages, or in strongly typed languages in which the types of variable arguments cannot be enforced at compilation time, or where there is implicit casting.
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.
Impact
Details
Quality Degradation
Scope: Other
Potential Mitigations
Phase(s)
Mitigation
Testing
Because this function call often produces incorrect behavior it will usually be detected during testing or normal operation of the product. During testing exercise all possible control paths will typically expose this weakness except in rare cases when the incorrect function call accidentally produces the correct results or if the provided argument type is very similar to the expected argument type.
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" (View-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.
Function Call with Incorrectly Specified Arguments
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
Implementation
Weakness Ordinalities
Ordinality
Description
Primary
(where the weakness exists independent of other weaknesses)
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.
(this CWE ID may 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
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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CERT C Secure Coding
EXP37-C
CWE More Specific
Call functions with the correct number and type of arguments
CERT C Secure Coding
FIO47-C
Imprecise
Use valid format strings
CERT C Secure Coding
POS34-C
Do not call putenv() with a pointer to an automatic variable as the argument
CERT C Secure Coding
STR37-C
Arguments to character handling functions must be representable as an unsigned char
CWE-687: Function Call With Incorrectly Specified Argument Value
Weakness ID: 687
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.
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Description
The product calls a function, procedure, or routine, but the caller specifies an argument that contains the wrong value, which may lead to resultant weaknesses.
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.
Impact
Details
Quality Degradation
Scope: Other
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" (View-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.
Function Call with Incorrectly Specified Arguments
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.
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
Implementation
Demonstrative Examples
Example 1
This Perl code intends to record whether a user authenticated successfully or not, and to exit if the user fails to authenticate. However, when it calls ReportAuth(), the third argument is specified as 0 instead of 1, so it does not exit.
(bad code)
Example Language: Perl
sub ReportAuth {
my ($username, $result, $fatal) = @_; PrintLog("auth: username=%s, result=%d", $username, $result); if (($result ne "success") && $fatal) {
die "Failed!\n";
}
}
sub PrivilegedFunc {
my $result = CheckAuth($username); ReportAuth($username, $result, 0); DoReallyImportantStuff();
}
Weakness Ordinalities
Ordinality
Description
Primary
(where the weakness exists independent of other weaknesses)
Detection
Methods
Method
Details
Manual Static Analysis
This might require an understanding of intended program behavior or design to determine whether the value is incorrect.
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.
(this CWE ID may 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
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
When primary, this weakness is most likely to occur in rarely-tested code, since the wrong value can change the semantic meaning of the program's execution and lead to obviously-incorrect behavior. It can also be resultant from issues in which the program assigns the wrong value to a variable, and that variable is later used in a function call. In that sense, this issue could be argued as having chaining relationships with many implementation errors in CWE.
CWE-209: Generation of Error Message Containing Sensitive Information
Weakness ID: 209
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:
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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
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.
Impact
Details
Read Application Data
Scope: Confidentiality
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(s)
Mitigation
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.
Implementation
Handle exceptions internally and do not display errors containing potentially sensitive information to a user.
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.
Implementation; Build and Compilation
Strategy: Compilation or Build Hardening
Debugging information should not make its way into a production release.
Implementation; Build and Compilation
Strategy: Environment Hardening
Debugging information should not make its way into a production release.
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.
System Configuration
Create default error pages or messages that do not leak any information.
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" (View-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.
Exposure of Sensitive Information to an Unauthorized Actor
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.
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.
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.
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.
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.
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.
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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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.
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
System Configuration
Operation
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
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 $e) {
If an exception occurs, the printed message exposes the location of the configuration file the script is using. An attacker can use this information to target the configuration file (perhaps exploiting a Path Traversal weakness). If the file can be read, the attacker could gain credentials for accessing the database. The attacker may also be able to replace the file with a malicious one, causing the application to use an arbitrary database.
Example 3
The following code generates an error message that leaks the full pathname of the configuration file.
# avoid CWE-22, CWE-78, others. ExitError("Bad hacker!") if ($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) {
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.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
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).
(where the weakness exists independent of other weaknesses)
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Detection
Methods
Method
Details
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
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.
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
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.)
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.
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).
Comprehensive Categorization: Sensitive Information Exposure
Vulnerability Mapping Notes
Usage
ALLOWED
(this CWE ID may 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.
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
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.
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.
CWE-754: Improper Check for Unusual or Exceptional Conditions
Weakness ID: 754
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:
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.
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Description
The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.
Extended Description
The programmer may assume that certain events or conditions will never occur or do not need to be worried about, such as low memory conditions, lack of access to resources due to restrictive permissions, or misbehaving clients or components. However, attackers may intentionally trigger these unusual conditions, thus violating the programmer's assumptions, possibly introducing instability, incorrect behavior, or a vulnerability.
Note that this entry is not exclusively about the use of exceptions and exception handling, which are mechanisms for both checking and handling unusual or unexpected conditions.
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.
Impact
Details
DoS: Crash, Exit, or Restart; Unexpected State
Scope: Integrity, Availability
The data which were produced as a result of a function call could be in a bad state upon return. If the return value is not checked, then this bad data may be used in operations, possibly leading to a crash or other unintended behaviors.
Potential Mitigations
Phase(s)
Mitigation
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.
Choose languages with features such as exception handling that force the programmer to anticipate unusual conditions that may generate exceptions. Custom exceptions may need to be developed to handle unusual business-logic conditions. Be careful not to pass sensitive exceptions back to the user (CWE-209, CWE-248).
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.
Implementation
If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248).
Effectiveness: High
Note: Using specific exceptions, and ensuring that exceptions are checked, helps programmers to anticipate and appropriately handle many unusual events that could occur.
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.
Exposing additional information to a potential attacker in the context of an exceptional condition can help the attacker determine what attack vectors are most likely to succeed beyond DoS.
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: Performing extensive input validation does not help with handling unusual conditions, but it will minimize their occurrences and will make it more difficult for attackers to trigger them.
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.
Architecture and Design
Use system limits, which should help to prevent resource exhaustion. However, the product should still handle low resource conditions since they may still occur.
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" (View-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.
Improper Check or Handling of Exceptional Conditions
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.
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.
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.
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.
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.
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.
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.
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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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).
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.
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.
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.
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
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
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
(Undetermined Prevalence)
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 code does not check to see if memory allocation succeeded before attempting to use the pointer returned by malloc().
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 simply 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 3
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 4
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 simply 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 5
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");
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 simply 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 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 7
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.
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 8
In the following C/C++ example the method outputStringToFile opens a file in the local filesystem and outputs a string to the file. The input parameters output and filename contain the string to output to the file and the name of the file respectively.
(bad code)
Example Language: C++
int outputStringToFile(char *output, char *filename) {
However, this code does not check the return values of the methods openFileToWrite, writeToFile, closeFile to verify that the file was properly opened and closed and that the string was successfully written to the file. The return values for these methods should be checked to determine if the method was successful and allow for detection of errors or unexpected conditions as in the following example.
(good code)
Example Language: C++
int outputStringToFile(char *output, char *filename) {
int isOutput = SUCCESS;
int isOpen = openFileToWrite(filename); if (isOpen == FAIL) {
printf("Unable to open file %s", filename); isOutput = FAIL;
} else {
int isWrite = writeToFile(output); if (isWrite == FAIL) {
printf("Unable to write to file %s", filename); isOutput = FAIL;
}
int isClose = closeFile(filename); if (isClose == FAIL)
isOutput = FAIL;
} return isOutput;
}
Example 9
In the following Java example the method readFromFile uses a FileReader object to read the contents of a file. The FileReader object is created using the File object readFile, the readFile object is initialized using the setInputFile method. The setInputFile method should be called before calling the readFromFile method.
(bad code)
Example Language: Java
private File readFile = null;
public void setInputFile(String inputFile) {
// create readFile File object from string containing name of file
}
public void readFromFile() {
try {
reader = new FileReader(readFile);
// read input file
} catch (FileNotFoundException ex) {...}
}
However, the readFromFile method does not check to see if the readFile object is null, i.e. has not been initialized, before creating the FileReader object and reading from the input file. The readFromFile method should verify whether the readFile object is null and output an error message and raise an exception if the readFile object is null, as in the following code.
(good code)
Example Language: Java
private File readFile = null;
public void setInputFile(String inputFile) {
// create readFile File object from string containing name of file
}
public void readFromFile() {
try {
if (readFile == null) {
System.err.println("Input file has not been set, call setInputFile method before calling openInputFile"); throw NullPointerException;
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
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.
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.
Detection
Methods
Method
Details
Automated Static Analysis
Automated static analysis may be useful for detecting unusual conditions involving system resources or common programming idioms, but not for violations of business rules.
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.
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.
Comprehensive Categorization: Improper Check or Handling of Exceptional Conditions
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
Sometimes, when a return value can be used to indicate an error, an unchecked return value is a code-layer instance of a missing application-layer check for exceptional conditions. However, return values are not always needed to communicate exceptional conditions. For example, expiration of resources, values passed by reference, asynchronously modified data, sockets, etc. may indicate exceptional conditions without the use of a return value.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
SEI CERT Perl Coding Standard
EXP31-PL
CWE More Abstract
Do not suppress or ignore exceptions
ISA/IEC 62443
Part 4-2
Req CR 3.5
ISA/IEC 62443
Part 4-2
Req CR 3.7
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-62]
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 1, "Exceptional Conditions," Page 22. 1st Edition. Addison Wesley. 2006.
[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.
CWE-703: Improper Check or Handling of Exceptional Conditions
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:
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.
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Description
The product does not properly anticipate or handle exceptional conditions that rarely occur during normal operation of the product.
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.
Impact
Details
Read Application Data; DoS: Crash, Exit, or Restart; Unexpected State
Scope: Confidentiality, Availability, Integrity
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" (View-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).
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 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.
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.
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 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.
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.
Relevant to the view "CISQ Quality Measures (2020)" (View-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.
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.
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.
Relevant to the view "CISQ Data Protection Measures" (View-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.
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.
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.
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
Operation
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
(Undetermined Prevalence)
Technologies
Class: Not Technology-Specific
(Undetermined Prevalence)
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)
Example Language: Java
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.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
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)
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
Method
Details
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:
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.
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).
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)
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.
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.
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Description
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.
Extended Description
Often, when functions or loops become complicated, some level of resource cleanup is needed throughout execution. Exceptions can disturb the flow of the code and prevent the necessary cleanup from happening.
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.
Impact
Details
Varies by Context
Scope: Other
The code could be left in a bad state.
Potential Mitigations
Phase(s)
Mitigation
Implementation
If one breaks from a loop or function by throwing an exception, make sure that cleanup happens or that you should exit the program. Use throwing exceptions sparsely.
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" (View-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.
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.
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
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.
threadLock=true; //do some stuff to truthvalue threadLock=false;
}
} catch (Exception e){
System.err.println("You did something bad"); if (something) return truthvalue;
} return truthvalue;
}
}
In this case, a thread might be left locked accidentally.
Detection
Methods
Method
Details
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
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.
(this CWE ID may 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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
CLASP
Improper cleanup on thrown exception
The CERT Oracle Secure Coding Standard for Java (2011)
ERR03-J
Restore prior object state on method failure
The CERT Oracle Secure Coding Standard for Java (2011)
ERR05-J
Do not let checked exceptions escape from a finally block
CWE-244: Improper Clearing of Heap Memory Before Release ('Heap Inspection')
Weakness ID: 244
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.
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Description
Using realloc() to resize buffers that store sensitive information can leave the sensitive information exposed to attack, because it is not removed from memory.
Extended Description
When sensitive data such as a password or an encryption key is not removed from memory, it could be exposed to an attacker using a "heap inspection" attack that reads the sensitive data using memory dumps or other methods. The realloc() function is commonly used to increase the size of a block of allocated memory. This operation often requires copying the contents of the old memory block into a new and larger block. This operation leaves the contents of the original block intact but inaccessible to the program, preventing the program from being able to scrub sensitive data from memory. If an attacker can later examine the contents of a memory dump, the sensitive data could be exposed.
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.
Impact
Details
Read Memory; Other
Scope: Confidentiality, Other
Be careful using vfork() and fork() in security sensitive code. The process state will not be cleaned up and will contain traces of data from past use.
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" (View-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.
Sensitive Information in Resource Not Removed Before Reuse
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.
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
Implementation
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
C
(Undetermined Prevalence)
C++
(Undetermined Prevalence)
Demonstrative Examples
Example 1
The following code calls realloc() on a buffer containing sensitive data:
There is an attempt to scrub the sensitive data from memory, but realloc() is used, so it could return a pointer to a different part of memory. The memory that was originally allocated for cleartext_buffer could still contain an uncleared copy of the data.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Cryptography library does not clear heap memory before release
Affected Resources
Memory
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.
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).
(this CWE ID may 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
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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
7 Pernicious Kingdoms
Heap Inspection
CERT C Secure Coding
MEM03-C
Clear sensitive information stored in reusable resources returned for reuse
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:
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Description
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.
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
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.
Impact
Details
Modify Application Data
Scope: Integrity
The communications between components can be modified in unexpected ways. Unexpected commands can be executed, bypassing other security mechanisms. Incoming data can be misinterpreted.
Execute Unauthorized Code or Commands
Scope: Integrity, Confidentiality, Availability, Access Control
The communications between components can be modified in unexpected ways. Unexpected commands can be executed, bypassing other security mechanisms. Incoming data can be misinterpreted.
Bypass Protection Mechanism
Scope: Confidentiality
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(s)
Mitigation
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.
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.
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.
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.
Architecture and Design
Use input validation as a defense-in-depth measure to reduce the likelihood of output encoding errors (see CWE-20).
Requirements
Fully specify which encodings are required by components that will be communicating with each other.
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
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" (View-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.
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.
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 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.
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 Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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).
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.
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
Implementation
Operation
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)
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.
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.
# 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.
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.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
OS command injection in backup software using shell metacharacters in a filename; correct behavior would require that this filename could not be changed.
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.
Cross-site scripting in chat application via a message, which normally might be allowed to contain arbitrary content.
Detection
Methods
Method
Details
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
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.
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.
(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
CWE-755: Improper Handling of Exceptional Conditions
Weakness ID: 755
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:
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.
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Description
The product does not handle or incorrectly handles an exceptional condition.
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.
Impact
Details
Other
Scope: Other
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" (View-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.
Improper Check or Handling of Exceptional Conditions
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.
Generation of 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.
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.
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.
Improper Handling of Insufficient Permissions or Privileges
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.
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.
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.
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 NullPointerException Catch to Detect NULL Pointer Dereference
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.
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.
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.
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.
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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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).
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
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
(Undetermined Prevalence)
Likelihood Of Exploit
Medium
Demonstrative Examples
Example 1
The following example attempts to resolve a hostname.
A DNS lookup failure will cause the Servlet to throw an exception.
Example 2
The following example attempts to allocate memory for a character. After the call to malloc, an if statement is used to check whether the malloc function failed.
(bad code)
Example Language: C
foo=malloc(sizeof(char)); //the next line checks to see if malloc failed if (foo==NULL) {
//We do nothing so we just ignore the error.
}
The conditional successfully detects a NULL return value from malloc indicating a failure, however it does not do anything to handle the problem. Unhandled errors may have unexpected results and may cause the program to crash or terminate.
Instead, the if block should contain statements that either attempt to fix the problem or notify the user that an error has occurred and continue processing or perform some cleanup and gracefully terminate the program. The following example notifies the user that the malloc function did not allocate the required memory resources and returns an error code.
(good code)
Example Language: C
foo=malloc(sizeof(char)); //the next line checks to see if malloc failed if (foo==NULL) {
printf("Malloc failed to allocate memory resources"); return -1;
}
Example 3
The following code mistakenly catches a NullPointerException.
(bad code)
Example Language: Java
try {
mysteryMethod();
} catch (NullPointerException npe) {
}
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
SDK for OPC Unified Architecture (OPC UA) server has uncaught exception when a socket is blocked for writing but the server tries to send an error
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)
virtual interrupt controller in a virtualization product allows crash of host by writing a certain invalid value to a register, which triggers a fatal error instead of returning an error code
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.
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.
CWE-241: Improper Handling of Unexpected Data Type
Weakness ID: 241
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.
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Description
The product does not handle or incorrectly handles when a particular element is not the expected type, e.g. it expects a digit (0-9) but is provided with a letter (A-Z).
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.
Impact
Details
Varies by Context; Unexpected State
Scope: Integrity, Other
Potential Mitigations
Phase(s)
Mitigation
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.
Implementation
Strategy: Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
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" (View-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.
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
Implementation
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
(Undetermined Prevalence)
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Anti-virus product has assert error when line length is non-numeric.
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.
(this CWE ID may 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
Research Gap
Probably under-studied.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
PLOVER
Wrong Data Type
CERT C Secure Coding
FIO37-C
CWE More Abstract
Do not assume that fgets() or fgetws() returns a nonempty string when successful
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:
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Description
The product does not properly handle when an input contains Unicode encoding.
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.
Impact
Details
Unexpected State
Scope: Integrity
Potential Mitigations
Phase(s)
Mitigation
Architecture and Design
Strategy: Input Validation
Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
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.
Implementation
Strategy: Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
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" (View-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.
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
Implementation
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
(Undetermined Prevalence)
Demonstrative Examples
Example 1
Windows provides the MultiByteToWideChar(), WideCharToMultiByte(), UnicodeToBytes(), and BytesToUnicode() functions to convert between arbitrary multibyte (usually ANSI) character strings and Unicode (wide character) strings. The size arguments to these functions are specified in different units, (one in bytes, the other in characters) making their use prone to error.
In a multibyte character string, each character occupies a varying number of bytes, and therefore the size of such strings is most easily specified as a total number of bytes. In Unicode, however, characters are always a fixed size, and string lengths are typically given by the number of characters they contain. Mistakenly specifying the wrong units in a size argument can lead to a buffer overflow.
The following function takes a username specified as a multibyte string and a pointer to a structure for user information and populates the structure with information about the specified user. Since Windows authentication uses Unicode for usernames, the username argument is first converted from a multibyte string to a Unicode string.
This function incorrectly passes the size of unicodeUser in bytes instead of characters. The call to MultiByteToWideChar() can therefore write up to (UNLEN+1)*sizeof(WCHAR) wide characters, or (UNLEN+1)*sizeof(WCHAR)*sizeof(WCHAR) bytes, to the unicodeUser array, which has only (UNLEN+1)*sizeof(WCHAR) bytes allocated.
If the username string contains more than UNLEN characters, the call to MultiByteToWideChar() will overflow the buffer unicodeUser.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Server allows remote attackers to read documents outside of the web root, and possibly execute arbitrary commands, via malformed URLs that contain Unicode encoded characters.
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.
(this CWE ID may 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
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.
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 8, "Character Sets and Unicode", Page 446. 1st Edition. Addison Wesley. 2006.
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:
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Description
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.
Extended Description
Not properly handling virtual filenames (e.g. AUX, CON, PRN, COM1, LPT1) can result in different types of vulnerabilities. In some cases an attacker can request a device via injection of a virtual filename in a URL, which may cause an error that leads to a denial of service or an error page that reveals sensitive information. A product that allows device names to bypass filtering runs the risk of an attacker injecting malicious code in a file with the name of a device.
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.
Impact
Details
DoS: Crash, Exit, or Restart; Read Application Data; Other
Scope: Availability, Confidentiality, Other
Potential Mitigations
Phase(s)
Mitigation
Implementation
Be familiar with the device names in the operating system where your system is deployed. Check input for these device names.
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" (View-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.
Improper Handling of File Names that Identify Virtual Resources
Background Details
Historically, there was a bug in the Windows operating system that caused a blue screen of death. Even after that issue was fixed DOS device names continue to be a factor.
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
Implementation
Operation
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
(Undetermined Prevalence)
Operating Systems
Class: Windows
(Undetermined Prevalence)
Likelihood Of Exploit
High
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Microsoft Windows 9x operating systems allow an attacker to cause a denial of service via a pathname that includes file device names, aka the "DOS Device in Path Name" vulnerability.
Product does not properly handle files whose names contain reserved MS-DOS device names, which can allow malicious code to bypass detection when it is installed, copied, or executed.
Server allows remote attackers to cause a denial of service (application crash) via a URL with a filename containing a .cgi extension and an MS-DOS device name.
Weakness Ordinalities
Ordinality
Description
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Affected Resources
File or Directory
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.
(this CWE ID may 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
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.
Taxonomy
Mappings
Mapped Taxonomy Name
Node ID
Fit
Mapped Node Name
PLOVER
Windows MS-DOS device names
CERT C Secure Coding
FIO32-C
CWE More Specific
Do not perform operations on devices that are only appropriate for files
The CERT Oracle Secure Coding Standard for Java (2011)
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 11, "Device Files", Page 666. 1st Edition. Addison Wesley. 2006.
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:
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.
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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
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.
Impact
Details
Read Memory; Read Application Data
Scope: Confidentiality
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.
Bypass Protection Mechanism
Scope: Access Control
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.
DoS: Crash, Exit, or Restart
Scope: Availability
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(s)
Mitigation
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.
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.
Implementation
Explicitly initialize all your variables and other data stores, either during declaration or just before the first usage.
Implementation
Pay close attention to complex conditionals that affect initialization, since some conditions might not perform the initialization.
Implementation
Avoid race conditions (CWE-362) during initialization routines.
Build and Compilation
Run or compile your product with settings that generate warnings about uninitialized variables or data.
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
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" (View-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.
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.
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.
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.
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.
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.
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.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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).
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.
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.
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.
Initialization of a Resource with an Insecure Default
Relevant to the view "CISQ Quality Measures (2020)" (View-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.
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.
Relevant to the view "CISQ Data Protection Measures" (View-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.
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.
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
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
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
(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.
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.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
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
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
Method
Details
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.
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
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
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
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.
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).
Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 7, "Variable Initialization", Page 312. 1st Edition. Addison Wesley. 2006.
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.
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Description
The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.
Extended Description
Input validation is a frequently-used technique
for checking potentially dangerous inputs in order to
ensure that the inputs are safe for processing within the
code, or when communicating with other components.
Input can consist of:
raw data - strings, numbers, parameters, file contents, etc.
metadata - information about the raw data, such as headers or size
Data can be simple or structured. Structured data
can be composed of many nested layers, composed of
combinations of metadata and raw data, with other simple or
structured data.
Many properties of raw data or metadata may need
to be validated upon entry into the code, such
as:
specified quantities such as size, length, frequency, price, rate, number of operations, time, etc.
implied or derived quantities, such as the actual size of a file instead of a specified size
indexes, offsets, or positions into more complex data structures
symbolic keys or other elements into hash tables, associative arrays, etc.
well-formedness, i.e. syntactic correctness - compliance with expected syntax
lexical token correctness - compliance with rules for what is treated as a token
specified or derived type - the actual type of the input (or what the input appears to be)
consistency - between individual data elements, between raw data and metadata, between references, etc.
conformance to domain-specific rules, e.g. business logic
equivalence - ensuring that equivalent inputs are treated the same
authenticity, ownership, or other attestations about the input, e.g. a cryptographic signature to prove the source of the data
Implied or derived properties of data must often
be calculated or inferred by the code itself. Errors in
deriving properties may be considered a contributing factor
to improper input validation.
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.
An attacker could provide unexpected values and cause a program crash or arbitrary control of resource allocation, leading to excessive consumption of resources such as memory and CPU.
Read Memory; Read Files or Directories
Scope: Confidentiality
An attacker could read confidential data if they are able to control resource references.
Modify Memory; Execute Unauthorized Code or Commands
Scope: Integrity, Confidentiality, Availability
An attacker could use malicious input to modify data or possibly alter control flow in unexpected ways, including arbitrary command execution.
Potential Mitigations
Phase(s)
Mitigation
Architecture and Design
Strategy: Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses. [REF-1109] [REF-1110] [REF-1111]
Architecture and Design
Strategy: Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design; Implementation
Strategy: Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: 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.
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.
Effectiveness: High
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.
Even though client-side checks provide minimal benefits with respect to server-side security, they are still useful. First, they can support intrusion detection. If the server receives input that should have been rejected by the client, then it may be an indication of an attack. Second, client-side error-checking can provide helpful feedback to the user about the expectations for valid input. Third, there may be a reduction in server-side processing time for accidental input errors, although this is typically a small savings.
Implementation
When your application combines data from multiple sources, perform the validation after the sources have been combined. The individual data elements may pass the validation step but violate the intended restrictions after they have been combined.
Implementation
Be especially careful to validate all input when invoking code that crosses language boundaries, such as from an interpreted language to native code. This could create an unexpected interaction between the language boundaries. Ensure that you are not violating any of the expectations of the language with which you are interfacing. For example, even though Java may not be susceptible to buffer overflows, providing a large argument in a call to native code might trigger an overflow.
Implementation
Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
Implementation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180, CWE-181). Make sure that your application does not inadvertently decode the same input twice (CWE-174). Such errors could be used to bypass allowlist schemes by introducing dangerous inputs after they have been checked. Use libraries such as the OWASP ESAPI Canonicalization control.
Consider performing repeated canonicalization until your input does not change any more. This will avoid double-decoding and similar scenarios, but it might inadvertently modify inputs that are allowed to contain properly-encoded dangerous content.
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
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" (View-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.
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.
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.
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.
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.
Improper Validation of Specified Quantity in Input
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.
Improper Validation of Specified Index, Position, or Offset in Input
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.
Improper Validation of Syntactic Correctness of Input
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.
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.
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.
Improper Validation of Unsafe Equivalence in Input
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.
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.
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
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.
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 Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
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.
Improper Restriction of Operations within the Bounds of a Memory Buffer
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.
Allocation of Resources Without Limits or Throttling
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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).
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.
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.
Relevant to the view "Seven Pernicious Kingdoms" (View-700)
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.
External Control of System or Configuration Setting
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.
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.
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.
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.
Struts: Form Bean Does Not Extend Validation Class
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.
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.
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.
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.
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.
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.
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.
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.
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 CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
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.
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.
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 Restriction of Operations within the Bounds of a Memory Buffer
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.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
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.
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.
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.
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.
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 Input to Select Classes or Code ('Unsafe Reflection')
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.
Use of Path Manipulation Function without Maximum-sized Buffer
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
Implementation
REALIZATION: This weakness is caused during implementation of an architectural security tactic.
If a programmer believes that an attacker cannot modify certain inputs, then the programmer might not perform any input validation at all. For example, in web applications, many programmers believe that cookies and hidden form fields can not be modified from a web browser (CWE-472), although they can be altered using a proxy or a custom program. In a client-server architecture, the programmer might assume that client-side security checks cannot be bypassed, even when a custom client could be written that skips those checks (CWE-602).
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 example demonstrates a shopping interaction in which the user is free to specify the quantity of items to be purchased and a total is calculated.
(bad code)
Example Language: Java
... public static final double price = 20.00; int quantity = currentUser.getAttribute("quantity"); double total = price * quantity; chargeUser(total); ...
The user has no control over the price variable, however the code does not prevent a negative value from being specified for quantity. If an attacker were to provide a negative value, then the user would have their account credited instead of debited.
Example 2
This example asks the user for a height and width of an m X n game board with a maximum dimension of 100 squares.
int m,n, error; board_square_t *board; printf("Please specify the board height: \n"); error = scanf("%d", &m); if ( EOF == error ){
die("No integer passed: Die evil hacker!\n");
} printf("Please specify the board width: \n"); error = scanf("%d", &n); if ( EOF == error ){
die("No integer passed: Die evil hacker!\n");
} if ( m > MAX_DIM || n > MAX_DIM ) {
die("Value too large: Die evil hacker!\n");
} board = (board_square_t*) malloc( m * n * sizeof(board_square_t)); ...
While this code checks to make sure the user cannot specify large, positive integers and consume too much memory, it does not check for negative values supplied by the user. As a result, an attacker can perform a resource consumption (CWE-400) attack against this program by specifying two, large negative values that will not overflow, resulting in a very large memory allocation (CWE-789) and possibly a system crash. Alternatively, an attacker can provide very large negative values which will cause an integer overflow (CWE-190) and unexpected behavior will follow depending on how the values are treated in the remainder of the program.
Example 3
The following example shows a PHP application in which the programmer attempts to display a user's birthday and homepage.
The programmer intended for $birthday to be in a date format and $homepage to be a valid URL. However, since the values are derived from an HTTP request, if an attacker can trick a victim into clicking a crafted URL with <script> tags providing the values for birthday and / or homepage, then the script will run on the client's browser when the web server echoes the content. Notice that even if the programmer were to defend the $birthday variable by restricting input to integers and dashes, it would still be possible for an attacker to provide a string of the form:
(attack code)
2009-01-09--
If this data were used in a SQL statement, it would treat the remainder of the statement as a comment. The comment could disable other security-related logic in the statement. In this case, encoding combined with input validation would be a more useful protection mechanism.
Furthermore, an XSS (CWE-79) attack or SQL injection (CWE-89) are just a few of the potential consequences when input validation is not used. Depending on the context of the code, CRLF Injection (CWE-93), Argument Injection (CWE-88), or Command Injection (CWE-77) may also be possible.
Example 4
The following example takes a user-supplied value to allocate an array of objects and then operates on the array.
(bad code)
Example Language: Java
private void buildList ( int untrustedListSize ){
if ( 0 > untrustedListSize ){
die("Negative value supplied for list size, die evil hacker!");
} Widget[] list = new Widget [ untrustedListSize ]; list[0] = new Widget();
}
This example attempts to build a list from a user-specified value, and even checks to ensure a non-negative value is supplied. If, however, a 0 value is provided, the code will build an array of size 0 and then try to store a new Widget in the first location, causing an exception to be thrown.
Example 5
This Android application has registered to handle a URL when sent an intent:
(bad code)
Example Language: Java
... IntentFilter filter = new IntentFilter("com.example.URLHandler.openURL"); MyReceiver receiver = new MyReceiver(); registerReceiver(receiver, filter); ...
public class UrlHandlerReceiver extends BroadcastReceiver {
@Override public void onReceive(Context context, Intent intent) {
String URL = intent.getStringExtra("URLToOpen"); int length = URL.length();
... }
}
}
The application assumes the URL will always be included in the intent. When the URL is not present, the call to getStringExtra() will return null, thus causing a null pointer exception when length() is called.
Selected Observed
Examples
Note: this is a curated list of examples for users to understand the variety of ways in which this
weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
Large language model (LLM) management tool does not
validate the format of a digest value (CWE-1287) from a
private, untrusted model registry, enabling relative
path traversal (CWE-23), a.k.a. Probllama
Chain: a learning management tool debugger uses external input to locate previous session logs (CWE-73) and does not properly validate the given path (CWE-20), allowing for filesystem path traversal using "../" sequences (CWE-24)
Chain: backslash followed by a newline can bypass a validation step (CWE-20), leading to eval injection (CWE-95), as exploited in the wild per CISA KEV.