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Common Weakness Enumeration

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Home > CWE List > VIEW SLICE: CWE-1430: Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses (4.16)  
ID

CWE VIEW: Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses

View ID: 1430
Vulnerability Mapping: PROHIBITED This CWE ID must not be used to map to real-world vulnerabilities
Type: Graph
Downloads: Booklet | CSV | XML
+ Objective
CWE entries in this view are listed in the 2024 CWE Top 25 Most Dangerous Software Weaknesses.
+ Audience
Stakeholder Description
Software Developers By following the CWE Top 25, developers are able to significantly reduce the number of weaknesses that occur in their software.
Product Customers Customers can use the weaknesses in this view in order to formulate independent evidence of a claim by a product vendor to have eliminated / mitigated the most dangerous weaknesses.
Educators Educators can use this view to focus curriculum and teachings on the most dangerous weaknesses.
+ 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.
Show Details:
1430 - Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 Input During Web Page Generation ('Cross-site Scripting') - (79)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 79 (Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'))
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. XSS HTML Injection CSS
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Out-of-bounds Write - (787)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 787 (Out-of-bounds Write)
The product writes data past the end, or before the beginning, of the intended buffer. Memory Corruption
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 SQL Command ('SQL Injection') - (89)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 89 (Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection'))
The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data. SQL injection SQLi
* Composite 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. Cross-Site Request Forgery (CSRF) - (352)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 352 (Cross-Site Request Forgery (CSRF))
The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request. Session Riding Cross Site Reference Forgery XSRF
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 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 traversal Path traversal
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Out-of-bounds Read - (125)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 125 (Out-of-bounds Read)
The product reads data past the end, or before the beginning, of the intended buffer. OOB read
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 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 injection Shell metacharacters OS Command Injection
* Variant 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)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 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 pointer UAF Use-After-Free
* Class 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. Missing Authorization - (862)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 862 (Missing Authorization)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action. AuthZ
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Unrestricted Upload of File with Dangerous Type - (434)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 434 (Unrestricted Upload of File with Dangerous Type)
The product allows the upload or transfer of dangerous file types that are automatically processed within its environment. Unrestricted File Upload
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 Control of Generation of Code ('Code Injection') - (94)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 94 (Improper Control of Generation of Code ('Code Injection'))
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
* Class 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)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 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 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 used in a Command ('Command Injection') - (77)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 77 (Improper Neutralization of Special Elements used in a Command ('Command Injection'))
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. Command injection
* Class 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 Authentication - (287)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 287 (Improper Authentication)
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. authentification AuthN AuthC
* Class 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 Privilege Management - (269)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 269 (Improper Privilege Management)
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Deserialization of Untrusted Data - (502)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 502 (Deserialization of Untrusted Data)
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. Marshaling, Unmarshaling Pickling, Unpickling PHP Object Injection
* Class 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 - (200)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 200 (Exposure of Sensitive Information to an Unauthorized Actor)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Information Disclosure Information Leak
* Class 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 Authorization - (863)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 863 (Incorrect Authorization)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. AuthZ
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Server-Side Request Forgery (SSRF) - (918)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 918 (Server-Side Request Forgery (SSRF))
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. XSPA SSRF
* Class 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)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 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 Overflow buffer overrun memory safety
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 476 (NULL Pointer Dereference)
The product dereferences a pointer that it expects to be valid but is NULL. NPD null deref NPE nil pointer dereference
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 Hard-coded Credentials - (798)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 798 (Use of Hard-coded Credentials)
The product contains hard-coded credentials, such as a password or cryptographic key.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 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. Overflow Wraparound wrap, wrap-around, wrap around
* Class 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. Uncontrolled Resource Consumption - (400)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 400 (Uncontrolled Resource Consumption)
The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. Resource Exhaustion
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 Authentication for Critical Function - (306)
1430 (Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses) > 306 (Missing Authentication for Critical Function)
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
+ Vulnerability Mapping Notes

Usage: PROHIBITED

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

Reason: View

Rationale:

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

Comments:

Use this View or other Views to search and navigate for the appropriate weakness.
+ References
[REF-1453] "2024 CWE Top 25 Most Dangerous Software Weaknesses". 2024-11-19. <https://cwe.mitre.org/top25>. URL validated: 2024-11-17.
+ View Metrics
CWEs in this view Total CWEs
Weaknesses 25 out of 940
Categories 0 out of 374
Views 0 out of 51
Total 25 out of 1365
+ Content History
+ Submissions
Submission Date Submitter Organization
2024-11-19
(CWE 4.16, 2024-11-19)
CWE Content Team MITRE

View Components

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CWE-352: Cross-Site Request Forgery (CSRF)

Weakness ID: 352 (Structure: Composite) 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.
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
View customized information:
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+ Description
The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.
+ Extended Description
When a web server is designed to receive a request from a client without any mechanism for verifying that it was intentionally sent, then it might be possible for an attacker to trick a client into making an unintentional request to the web server which will be treated as an authentic request. This can be done via a URL, image load, XMLHttpRequest, etc. and can result in exposure of data or unintended code execution.
+ Alternate Terms
Session Riding
Cross Site Reference Forgery
XSRF
+ Common Consequences
Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Scope Impact Likelihood
Confidentiality
Integrity
Availability
Non-Repudiation
Access Control

Technical Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism; Read Application Data; Modify Application Data; DoS: Crash, Exit, or Restart

The consequences will vary depending on the nature of the functionality that is vulnerable to CSRF. An attacker could effectively perform any operations as the victim. If the victim is an administrator or privileged user, the consequences may include obtaining complete control over the web application - deleting or stealing data, uninstalling the product, or using it to launch other attacks against all of the product's users. Because the attacker has the identity of the victim, the scope of CSRF is limited only by the victim's privileges.
+ Potential Mitigations

Phase: Architecture and Design

Strategy: Libraries or Frameworks

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

For example, use anti-CSRF packages such as the OWASP CSRFGuard. [REF-330]

Another example is the ESAPI Session Management control, which includes a component for CSRF. [REF-45]

Phase: Implementation

Ensure that the application is free of cross-site scripting issues (CWE-79), because most CSRF defenses can be bypassed using attacker-controlled script.

Phase: Architecture and Design

Generate a unique nonce for each form, place the nonce into the form, and verify the nonce upon receipt of the form. Be sure that the nonce is not predictable (CWE-330). [REF-332]
Note: Note that this can be bypassed using XSS (CWE-79).

Phase: Architecture and Design

Identify especially dangerous operations. When the user performs a dangerous operation, send a separate confirmation request to ensure that the user intended to perform that operation.
Note: Note that this can be bypassed using XSS (CWE-79).

Phase: Architecture and Design

Use the "double-submitted cookie" method as described by Felten and Zeller:

When a user visits a site, the site should generate a pseudorandom value and set it as a cookie on the user's machine. The site should require every form submission to include this value as a form value and also as a cookie value. When a POST request is sent to the site, the request should only be considered valid if the form value and the cookie value are the same.

Because of the same-origin policy, an attacker cannot read or modify the value stored in the cookie. To successfully submit a form on behalf of the user, the attacker would have to correctly guess the pseudorandom value. If the pseudorandom value is cryptographically strong, this will be prohibitively difficult.

This technique requires Javascript, so it may not work for browsers that have Javascript disabled. [REF-331]

Note: Note that this can probably be bypassed using XSS (CWE-79), or when using web technologies that enable the attacker to read raw headers from HTTP requests.

Phase: Architecture and Design

Do not use the GET method for any request that triggers a state change.

Phase: Implementation

Check the HTTP Referer header to see if the request originated from an expected page. This could break legitimate functionality, because users or proxies may have disabled sending the Referer for privacy reasons.
Note: Note that this can be bypassed using XSS (CWE-79). An attacker could use XSS to generate a spoofed Referer, or to generate a malicious request from a page whose Referer would be allowed.
+ Composite Components
Nature Type ID Name
Requires 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. 346 Origin Validation Error
Requires 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. 441 Unintended Proxy or Intermediary ('Confused Deputy')
Requires 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. 613 Insufficient Session Expiration
Requires 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. 642 External Control of Critical State Data
+ Relationships
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Research Concepts" (CWE-1000)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 345 Insufficient Verification of Data Authenticity
PeerOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CanFollow Variant 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. 1275 Sensitive Cookie with Improper SameSite Attribute
Section Help 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 "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 345 Insufficient Verification of Data Authenticity
Section Help 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 "Architectural Concepts" (CWE-1008)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1019 Validate Inputs
+ Modes Of Introduction
Section HelpThe 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 REALIZATION: This weakness is caused during implementation of an architectural security tactic.
+ Applicable Platforms
Section HelpThis 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

Web Server (Undetermined Prevalence)

+ Likelihood Of Exploit
Medium
+ Demonstrative Examples

Example 1

This example PHP code attempts to secure the form submission process by validating that the user submitting the form has a valid session. A CSRF attack would not be prevented by this countermeasure because the attacker forges a request through the user's web browser in which a valid session already exists.

The following HTML is intended to allow a user to update a profile.

(bad code)
Example Language: HTML 
<form action="/url/profile.php" method="post">
<input type="text" name="firstname"/>
<input type="text" name="lastname"/>
<br/>
<input type="text" name="email"/>
<input type="submit" name="submit" value="Update"/>
</form>

profile.php contains the following code.

(bad code)
Example Language: PHP 
// initiate the session in order to validate sessions

session_start();

//if the session is registered to a valid user then allow update

if (! session_is_registered("username")) {

echo "invalid session detected!";

// Redirect user to login page
[...]

exit;
}

// The user session is valid, so process the request

// and update the information

update_profile();

function update_profile {

// read in the data from $POST and send an update

// to the database
SendUpdateToDatabase($_SESSION['username'], $_POST['email']);
[...]
echo "Your profile has been successfully updated.";
}

This code may look protected since it checks for a valid session. However, CSRF attacks can be staged from virtually any tag or HTML construct, including image tags, links, embed or object tags, or other attributes that load background images.

The attacker can then host code that will silently change the username and email address of any user that visits the page while remaining logged in to the target web application. The code might be an innocent-looking web page such as:

(attack code)
Example Language: HTML 
<SCRIPT>
function SendAttack () {
form.email = "attacker@example.com";
// send to profile.php
form.submit();
}
</SCRIPT>

<BODY onload="javascript:SendAttack();">

<form action="http://victim.example.com/profile.php" id="form" method="post">
<input type="hidden" name="firstname" value="Funny">
<input type="hidden" name="lastname" value="Joke">
<br/>
<input type="hidden" name="email">
</form>

Notice how the form contains hidden fields, so when it is loaded into the browser, the user will not notice it. Because SendAttack() is defined in the body's onload attribute, it will be automatically called when the victim loads the web page.

Assuming that the user is already logged in to victim.example.com, profile.php will see that a valid user session has been established, then update the email address to the attacker's own address. At this stage, the user's identity has been compromised, and messages sent through this profile could be sent to the attacker's address.


+ Observed Examples
Reference Description
Add user accounts via a URL in an img tag
Add user accounts via a URL in an img tag
Arbitrary code execution by specifying the code in a crafted img tag or URL
Gain administrative privileges via a URL in an img tag
Delete a victim's information via a URL or an img tag
Change another user's settings via a URL or an img tag
Perform actions as administrator via a URL or an img tag
modify password for the administrator
CMS allows modification of configuration via CSRF attack against the administrator
web interface allows password changes or stopping a virtual machine via CSRF
+ Detection Methods

Manual Analysis

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

Specifically, manual analysis can be useful for finding this weakness, and for minimizing false positives assuming an understanding of business logic. However, it might not achieve desired code coverage within limited time constraints. For black-box analysis, if credentials are not known for privileged accounts, then the most security-critical portions of the application may not receive sufficient attention.

Consider using OWASP CSRFTester to identify potential issues and aid in manual analysis.

Effectiveness: High

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

Automated Static Analysis

CSRF is currently difficult to detect reliably using automated techniques. This is because each application has its own implicit security policy that dictates which requests can be influenced by an outsider and automatically performed on behalf of a user, versus which requests require strong confidence that the user intends to make the request. For example, a keyword search of the public portion of a web site is typically expected to be encoded within a link that can be launched automatically when the user clicks on the link.

Effectiveness: Limited

Automated Static Analysis - Binary or Bytecode

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

Cost effective for partial coverage:
  • Bytecode Weakness Analysis - including disassembler + source code weakness analysis
  • Binary Weakness Analysis - including disassembler + source code weakness analysis

Effectiveness: SOAR Partial

Manual Static Analysis - Binary or Bytecode

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

Cost effective for partial coverage:
  • Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

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

Highly cost effective:
  • Web Application Scanner

Effectiveness: High

Dynamic Analysis with Manual Results Interpretation

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

Highly cost effective:
  • Fuzz Tester
  • Framework-based Fuzzer

Effectiveness: High

Manual Static Analysis - Source Code

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

Cost effective for partial coverage:
  • Focused Manual Spotcheck - Focused manual analysis of source
  • Manual Source Code Review (not inspections)

Effectiveness: SOAR Partial

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:

Cost effective for partial coverage:
  • Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)
  • Formal Methods / Correct-By-Construction

Effectiveness: SOAR Partial

+ Memberships
Section HelpThis 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 ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 635 Weaknesses Originally Used by NVD from 2008 to 2016
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 716 OWASP Top Ten 2007 Category A5 - Cross Site Request Forgery (CSRF)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 751 2009 Top 25 - Insecure Interaction Between Components
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 801 2010 Top 25 - Insecure Interaction Between Components
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 814 OWASP Top Ten 2010 Category A5 - Cross-Site Request Forgery(CSRF)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 864 2011 Top 25 - Insecure Interaction Between Components
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 884 CWE Cross-section
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 936 OWASP Top Ten 2013 Category A8 - Cross-Site Request Forgery (CSRF)
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1200 Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1337 Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1345 OWASP Top Ten 2021 Category A01:2021 - Broken Access Control
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1350 Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1387 Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1411 Comprehensive Categorization: Insufficient Verification of Data Authenticity
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1425 Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf ViewView - 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). 1430 Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses
+ Vulnerability Mapping Notes

Usage: ALLOWED

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

Reason: Other

Rationale:

This is a well-known Composite of multiple weaknesses that must all occur simultaneously, although it is attack-oriented in nature.

Comments:

While attack-oriented composites are supported in CWE, they have not been a focus of research. There is a chance that future research or CWE scope clarifications will change or deprecate them. Perform root-cause analysis to determine if other weaknesses allow CSRF attacks to occur, and map to those weaknesses. For example, predictable CSRF tokens might allow bypass of CSRF protection mechanisms; if this occurs, they might be better characterized as randomness/predictability weaknesses.
+ Notes

Relationship

There can be a close relationship between XSS and CSRF (CWE-352). An attacker might use CSRF in order to trick the victim into submitting requests to the server in which the requests contain an XSS payload. A well-known example of this was the Samy worm on MySpace [REF-956]. The worm used XSS to insert malicious HTML sequences into a user's profile and add the attacker as a MySpace friend. MySpace friends of that victim would then execute the payload to modify their own profiles, causing the worm to propagate exponentially. Since the victims did not intentionally insert the malicious script themselves, CSRF was a root cause.

Theoretical

The CSRF topology is multi-channel:

  • Attacker (as outsider) to intermediary (as user). The interaction point is either an external or internal channel.
  • Intermediary (as user) to server (as victim). The activation point is an internal channel.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
PLOVER Cross-Site Request Forgery (CSRF)
OWASP Top Ten 2007 A5 Exact Cross Site Request Forgery (CSRF)
WASC 9 Cross-site Request Forgery
+ References
[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 2: Web-Server Related Vulnerabilities (XSS, XSRF, and Response Splitting)." Page 37. McGraw-Hill. 2010.
[REF-329] Peter W. "Cross-Site Request Forgeries (Re: The Dangers of Allowing Users to Post Images)". Bugtraq. <http://marc.info/?l=bugtraq&m=99263135911884&w=2>.
[REF-330] OWASP. "Cross-Site Request Forgery (CSRF) Prevention Cheat Sheet". <http://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)_Prevention_Cheat_Sheet>.
[REF-331] Edward W. Felten and William Zeller. "Cross-Site Request Forgeries: Exploitation and Prevention". 2008-10-18. <https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.147.1445>. URL validated: 2023-04-07.
[REF-332] Robert Auger. "CSRF - The Cross-Site Request Forgery (CSRF/XSRF) FAQ". <https://www.cgisecurity.com/csrf-faq.html>. URL validated: 2023-04-07.
[REF-333] "Cross-site request forgery". Wikipedia. 2008-12-22. <https://en.wikipedia.org/wiki/Cross-site_request_forgery>. URL validated: 2023-04-07.
[REF-334] Jason Lam. "Top 25 Series - Rank 4 - Cross Site Request Forgery". SANS Software Security Institute. 2010-03-03. <http://software-security.sans.org/blog/2010/03/03/top-25-series-rank-4-cross-site-request-forgery>.
[REF-335] Jeff Atwood. "Preventing CSRF and XSRF Attacks". 2008-10-14. <https://blog.codinghorror.com/preventing-csrf-and-xsrf-attacks/>. URL validated: 2023-04-07.
[REF-45] OWASP. "OWASP Enterprise Security API (ESAPI) Project". <http://www.owasp.org/index.php/ESAPI>.
[REF-956] Wikipedia. "Samy (computer worm)". <https://en.wikipedia.org/wiki/Samy_(computer_worm)>. URL validated: 2018-01-16.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
PLOVER
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Time_of_Introduction
2008-09-08 CWE Content Team MITRE
updated Alternate_Terms, Description, Relationships, Other_Notes, Relationship_Notes, Taxonomy_Mappings
2009-01-12 CWE Content Team MITRE
updated Applicable_Platforms, Description, Likelihood_of_Exploit, Observed_Examples, Other_Notes, Potential_Mitigations, References, Relationship_Notes, Relationships, Research_Gaps, Theoretical_Notes
2009-03-10 CWE Content Team MITRE
updated Potential_Mitigations
2009-05-20 Tom Stracener
Added demonstrative example for profile.
2009-05-27 CWE Content Team MITRE
updated Demonstrative_Examples, Related_Attack_Patterns
2009-12-28 CWE Content Team MITRE
updated Common_Consequences, Demonstrative_Examples, Detection_Factors, Likelihood_of_Exploit, Observed_Examples, Potential_Mitigations, Time_of_Introduction
2010-02-16 CWE Content Team MITRE
updated Applicable_Platforms, Detection_Factors, References, Relationships, Taxonomy_Mappings
2010-06-21 CWE Content Team MITRE
updated Common_Consequences, Detection_Factors, Potential_Mitigations, References, Relationships
2010-09-27 CWE Content Team MITRE
updated Potential_Mitigations
2011-03-29 CWE Content Team MITRE
updated Description
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2011-06-27 CWE Content Team MITRE
updated Relationships
2011-09-13 CWE Content Team MITRE
updated Potential_Mitigations, References
2012-05-11 CWE Content Team MITRE
updated Related_Attack_Patterns, Relationships
2012-10-30 CWE Content Team MITRE
updated Potential_Mitigations
2013-02-21 CWE Content Team MITRE
updated Relationships
2013-07-17 CWE Content Team MITRE
updated References, Relationships
2014-07-30 CWE Content Team MITRE
updated Detection_Factors
2015-12-07 CWE Content Team MITRE
updated Relationships
2017-11-08 CWE Content Team MITRE
updated Applicable_Platforms, Likelihood_of_Exploit, Modes_of_Introduction, References, Relationships
2018-03-27 CWE Content Team MITRE
updated References, Relationship_Notes, Research_Gaps
2019-09-19 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated Relationships
2020-06-25 CWE Content Team MITRE
updated Relationships, Theoretical_Notes
2020-08-20 CWE Content Team MITRE
updated Relationships
2021-07-20 CWE Content Team MITRE
updated Relationships
2021-10-28 CWE Content Team MITRE
updated Relationships
2022-06-28 CWE Content Team MITRE
updated Relationships
2023-04-27 CWE Content Team MITRE
updated References, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes, Relationships
2024-11-19
(CWE 4.16, 2024-11-19)
CWE Content Team MITRE
updated Relationships

CWE-502: Deserialization of Untrusted Data

Weakness ID: 502
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. Diagram for CWE-502
+ Alternate Terms
Marshaling, Unmarshaling:
Marshaling and unmarshaling are effectively synonyms for serialization and deserialization, respectively.
Pickling, Unpickling:
In Python, the "pickle" functionality is used to perform serialization and deserialization.
PHP Object Injection:
Some PHP application researchers use this term when attacking unsafe use of the unserialize() function; but it is also used for CWE-915.
+ Common Consequences
Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Scope Impact Likelihood
Integrity

Technical Impact: Modify Application Data; Unexpected State

Attackers can modify unexpected objects or data that was assumed to be safe from modification. Deserialized data or code could be modified without using the provided accessor functions, or unexpected functions could be invoked.
Availability

Technical Impact: DoS: Resource Consumption (CPU)

If a function is making an assumption on when to terminate, based on a sentry in a string, it could easily never terminate.
Other

Technical Impact: Varies by Context

The consequences can vary widely, because it depends on which objects or methods are being deserialized, and how they are used. Making an assumption that the code in the deserialized object is valid is dangerous and can enable exploitation. One example is attackers using gadget chains to perform unauthorized actions, such as generating a shell.
+ Potential Mitigations

Phases: Architecture and Design; Implementation

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

Phase: Implementation

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

Phase: Implementation

Explicitly define a final object() to prevent deserialization.

Phases: Architecture and Design; Implementation

Make fields transient to protect them from deserialization.

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

Phase: Implementation

Avoid having unnecessary types or gadgets (a sequence of instances and method invocations that can self-execute during the deserialization process, often found in libraries) available that can be leveraged for malicious ends. This limits the potential for unintended or unauthorized types and gadgets to be leveraged by the attacker. Add only acceptable classes to an allowlist. Note: new gadgets are constantly being discovered, so this alone is not a sufficient mitigation.

Phases: Architecture and Design; Implementation

Employ cryptography of the data or code for protection. However, it's important to note that it would still be client-side security. This is risky because if the client is compromised then the security implemented on the client (the cryptography) can be bypassed.
+ Relationships
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Research Concepts" (CWE-1000)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 913 Improper Control of Dynamically-Managed Code Resources
PeerOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 915 Improperly Controlled Modification of Dynamically-Determined Object Attributes
Section Help 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 "Software Development" (CWE-699)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 399 Resource Management Errors
Section Help 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 "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 913 Improper Control of Dynamically-Managed Code Resources
Section Help 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 "Architectural Concepts" (CWE-1008)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1019 Validate Inputs
+ Background Details
Serialization and deserialization refer to the process of taking program-internal object-related data, packaging it in a way that allows the data to be externally stored or transferred ("serialization"), then extracting the serialized data to reconstruct the original object ("deserialization").
+ Modes Of Introduction
Section HelpThe 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
+ Applicable Platforms
Section HelpThis 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

Java (Undetermined Prevalence)

Ruby (Undetermined Prevalence)

PHP (Undetermined Prevalence)

Python (Undetermined Prevalence)

JavaScript (Undetermined Prevalence)

Technologies

Class: ICS/OT (Often Prevalent)

+ Likelihood Of Exploit
Medium
+ Demonstrative Examples

Example 1

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

(bad code)
Example Language: Java 
try {
File file = new File("object.obj");
ObjectInputStream in = new ObjectInputStream(new FileInputStream(file));
javax.swing.JButton button = (javax.swing.JButton) in.readObject();
in.close();
}

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

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

(good code)
Example Language: Java 
private final void readObject(ObjectInputStream in) throws java.io.IOException {
throw new java.io.IOException("Cannot be deserialized"); }

Example 2

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

(bad code)
Example Language: Python 
try {
class ExampleProtocol(protocol.Protocol):
def dataReceived(self, data):

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

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

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


+ Observed Examples
Reference Description
chain: bypass of untrusted deserialization issue (CWE-502) by using an assumed-trusted class (CWE-183)
Deserialization issue in commonly-used Java library allows remote execution.
Deserialization issue in commonly-used Java library allows remote execution.
Use of PHP unserialize function on untrusted input allows attacker to modify application configuration.
Use of PHP unserialize function on untrusted input in content management system might allow code execution.
Use of PHP unserialize function on untrusted input in content management system allows code execution using a crafted cookie value.
Content management system written in PHP allows unserialize of arbitrary objects, possibly allowing code execution.
Python script allows local users to execute code via pickled data.
Unsafe deserialization using pickle in a Python script.
Web browser allows execution of native methods via a crafted string to a JavaScript function that deserializes the string.
+ Detection Methods

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
Section HelpThis 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 CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 858 The CERT Oracle Secure Coding Standard for Java (2011) Chapter 15 - Serialization (SER)
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 884 CWE Cross-section
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 994 SFP Secondary Cluster: Tainted Input to Variable
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1034 OWASP Top Ten 2017 Category A8 - Insecure Deserialization
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1148 SEI CERT Oracle Secure Coding Standard for Java - Guidelines 14. Serialization (SER)
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1200 Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1308 CISQ Quality Measures - Security
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1337 Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1340 CISQ Data Protection Measures
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1350 Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1354 OWASP Top Ten 2021 Category A08:2021 - Software and Data Integrity Failures
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1387 Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1415 Comprehensive Categorization: Resource Control
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1425 Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf ViewView - 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). 1430 Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses
+ 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.
+ Notes

Maintenance

The relationships between CWE-502 and CWE-915 need further exploration. CWE-915 is more narrowly scoped to object modification, and is not necessarily used for deserialization.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
CLASP Deserialization of untrusted data
The CERT Oracle Secure Coding Standard for Java (2011) SER01-J Do not deviate from the proper signatures of serialization methods
The CERT Oracle Secure Coding Standard for Java (2011) SER03-J Do not serialize unencrypted, sensitive data
The CERT Oracle Secure Coding Standard for Java (2011) SER06-J Make defensive copies of private mutable components during deserialization
The CERT Oracle Secure Coding Standard for Java (2011) SER08-J Do not use the default serialized form for implementation defined invariants
Software Fault Patterns SFP25 Tainted input to variable
+ References
[REF-18] Secure Software, Inc.. "The CLASP Application Security Process". 2005. <https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf>. URL validated: 2024-11-17.
[REF-461] Matthias Kaiser. "Exploiting Deserialization Vulnerabilities in Java". 2015-10-28. <https://www.slideshare.net/codewhitesec/exploiting-deserialization-vulnerabilities-in-java-54707478>. URL validated: 2023-04-07.
[REF-462] Sam Thomas. "PHP unserialization vulnerabilities: What are we missing?". 2015-08-27. <https://www.slideshare.net/_s_n_t/php-unserialization-vulnerabilities-what-are-we-missing>. URL validated: 2023-04-07.
[REF-463] Gabriel Lawrence and Chris Frohoff. "Marshalling Pickles: How deserializing objects can ruin your day". 2015-01-28. <https://www.slideshare.net/frohoff1/appseccali-2015-marshalling-pickles>. URL validated: 2023-04-07.
[REF-464] Heine Deelstra. "Unserializing user-supplied data, a bad idea". 2010-08-25. <https://drupalsun.com/heine/2010/08/25/unserializing-user-supplied-data-bad-idea>. URL validated: 2023-04-07.
[REF-465] Manish S. Saindane. "Black Hat EU 2010 - Attacking Java Serialized Communication". 2010-04-26. <https://www.slideshare.net/msaindane/black-hat-eu-2010-attacking-java-serialized-communication>. URL validated: 2023-04-07.
[REF-466] Nadia Alramli. "Why Python Pickle is Insecure". 2009-09-09. <http://michael-rushanan.blogspot.com/2012/10/why-python-pickle-is-insecure.html>. URL validated: 2023-04-07.
[REF-467] Nelson Elhage. "Exploiting misuse of Python's "pickle"". 2011-03-20. <https://blog.nelhage.com/2011/03/exploiting-pickle/>.
[REF-468] Chris Frohoff. "Deserialize My Shorts: Or How I Learned to Start Worrying and Hate Java Object Deserialization". 2016-03-21. <https://speakerdeck.com/frohoff/owasp-sd-deserialize-my-shorts-or-how-i-learned-to-start-worrying-and-hate-java-object-deserialization>. URL validated: 2023-04-07.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
CLASP
+ Contributions
Contribution Date Contributor Organization
2024-02-29
(CWE 4.16, 2024-11-19)
Abhi Balakrishnan
Contributed usability diagram concepts used by the CWE team
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Time_of_Introduction
2008-09-08 CWE Content Team MITRE
updated Common_Consequences, Description, Relationships, Other_Notes, Taxonomy_Mappings
2009-10-29 CWE Content Team MITRE
updated Description, Other_Notes, Potential_Mitigations
2011-06-01 CWE Content Team MITRE
updated Common_Consequences, Relationships, Taxonomy_Mappings
2012-05-11 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2012-10-30 CWE Content Team MITRE
updated Demonstrative_Examples
2013-02-21 CWE Content Team MITRE
updated Alternate_Terms, Applicable_Platforms, Background_Details, Common_Consequences, Maintenance_Notes, Observed_Examples, Potential_Mitigations, References, Relationships
2014-07-30 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2015-12-07 CWE Content Team MITRE
updated Observed_Examples, References, Relationships
2017-05-03 CWE Content Team MITRE
updated Applicable_Platforms, Demonstrative_Examples, Description, Potential_Mitigations, References
2017-11-08 CWE Content Team MITRE
updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Modes_of_Introduction, Potential_Mitigations, References, Relationships
2018-03-27 CWE Content Team MITRE
updated Relationships
2019-01-03 CWE Content Team MITRE
updated Related_Attack_Patterns, Relationships, Taxonomy_Mappings
2019-06-20 CWE Content Team MITRE
updated Type
2019-09-19 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated Observed_Examples, References, Relationships
2020-06-25 CWE Content Team MITRE
updated Alternate_Terms, Potential_Mitigations
2020-08-20 CWE Content Team MITRE
updated Relationships
2020-12-10 CWE Content Team MITRE
updated Relationships
2021-07-20 CWE Content Team MITRE
updated Relationships
2021-10-28 CWE Content Team MITRE
updated Relationships
2022-06-28 CWE Content Team MITRE
updated Relationships
2022-10-13 CWE Content Team MITRE
updated Applicable_Platforms
2023-01-31 CWE Content Team MITRE
updated Description
2023-04-27 CWE Content Team MITRE
updated Detection_Factors, References, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes, Relationships
2024-11-19
(CWE 4.16, 2024-11-19)
CWE Content Team MITRE
updated Common_Consequences, Description, Diagram, Potential_Mitigations, Relationships

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

Weakness ID: 200
Vulnerability Mapping: DISCOURAGED This CWE ID should not be used to map to real-world vulnerabilities
Abstraction: Class 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.
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.
×

Edit Custom Filter


+ Description
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
+ Extended Description

There are many different kinds of mistakes that introduce information exposures. The severity of the error can range widely, depending on the context in which the product operates, the type of sensitive information that is revealed, and the benefits it may provide to an attacker. Some kinds of sensitive information include:

  • private, personal information, such as personal messages, financial data, health records, geographic location, or contact details
  • system status and environment, such as the operating system and installed packages
  • business secrets and intellectual property
  • network status and configuration
  • the product's own code or internal state
  • metadata, e.g. logging of connections or message headers
  • indirect information, such as a discrepancy between two internal operations that can be observed by an outsider

Information might be sensitive to different parties, each of which may have their own expectations for whether the information should be protected. These parties include:

  • the product's own users
  • people or organizations whose information is created or used by the product, even if they are not direct product users
  • the product's administrators, including the admins of the system(s) and/or networks on which the product operates
  • the developer

Information exposures can occur in different ways:

  • the code explicitly inserts sensitive information into resources or messages that are intentionally made accessible to unauthorized actors, but should not contain the information - i.e., the information should have been "scrubbed" or "sanitized"
  • a different weakness or mistake indirectly inserts the sensitive information into resources, such as a web script error revealing the full system path of the program.
  • the code manages resources that intentionally contain sensitive information, but the resources are unintentionally made accessible to unauthorized actors. In this case, the information exposure is resultant - i.e., a different weakness enabled the access to the information in the first place.

It is common practice to describe any loss of confidentiality as an "information exposure," but this can lead to overuse of CWE-200 in CWE mapping. From the CWE perspective, loss of confidentiality is a technical impact that can arise from dozens of different weaknesses, such as insecure file permissions or out-of-bounds read. CWE-200 and its lower-level descendants are intended to cover the mistakes that occur in behaviors that explicitly manage, store, transfer, or cleanse sensitive information.

+ Alternate Terms
Information Disclosure:
This term is frequently used in vulnerability advisories to describe a consequence or technical impact, for any vulnerability that has a loss of confidentiality. Often, CWE-200 can be misused to represent the loss of confidentiality, even when the mistake - i.e., the weakness - is not directly related to the mishandling of the information itself, such as an out-of-bounds read that accesses sensitive memory contents; here, the out-of-bounds read is the primary weakness, not the disclosure of the memory. In addition, this phrase is also used frequently in policies and legal documents, but it does not refer to any disclosure of security-relevant information.
Information Leak:
This is a frequently used term, however the "leak" term has multiple uses within security. In some cases it deals with the accidental exposure of information from a different weakness, but in other cases (such as "memory leak"), this deals with improper tracking of resources, which can lead to exhaustion. As a result, CWE is actively avoiding usage of the "leak" term.
+ Common Consequences
Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Scope Impact Likelihood
Confidentiality

Technical Impact: Read Application Data

+ Potential Mitigations

Phase: Architecture and Design

Strategy: Separation of Privilege

Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.

Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

+ Relationships
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Research Concepts" (CWE-1000)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 668 Exposure of Resource to Wrong Sphere
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 201 Insertion of Sensitive Information Into Sent Data
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 203 Observable Discrepancy
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 209 Generation of Error Message Containing Sensitive Information
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 213 Exposure of Sensitive Information Due to Incompatible Policies
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 215 Insertion of Sensitive Information Into Debugging Code
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 359 Exposure of Private Personal Information to an Unauthorized Actor
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 497 Exposure of Sensitive System Information to an Unauthorized Control Sphere
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 538 Insertion of Sensitive Information into Externally-Accessible File or Directory
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 1258 Exposure of Sensitive System Information Due to Uncleared Debug Information
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 1273 Device Unlock Credential Sharing
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 1295 Debug Messages Revealing Unnecessary Information
CanFollow Variant 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. 498 Cloneable Class Containing Sensitive Information
CanFollow Variant 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. 499 Serializable Class Containing Sensitive Data
CanFollow Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 1272 Sensitive Information Uncleared Before Debug/Power State Transition
Section Help 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 "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
Nature Type ID Name
MemberOf View View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1003 Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 203 Observable Discrepancy
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 209 Generation of Error Message Containing Sensitive Information
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 532 Insertion of Sensitive Information into Log File
+ Modes Of Introduction
Section HelpThe 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
+ Applicable Platforms
Section HelpThis 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: Mobile (Undetermined Prevalence)

+ Likelihood Of Exploit
High
+ Demonstrative Examples

Example 1

The following code checks validity of the supplied username and password and notifies the user of a successful or failed login.

(bad code)
Example Language: Perl 
my $username=param('username');
my $password=param('password');

if (IsValidUsername($username) == 1)
{
if (IsValidPassword($username, $password) == 1)
{
print "Login Successful";
}
else
{
print "Login Failed - incorrect password";
}
}
else
{
print "Login Failed - unknown username";
}

In the above code, there are different messages for when an incorrect username is supplied, versus when the username is correct but the password is wrong. This difference enables a potential attacker to understand the state of the login function, and could allow an attacker to discover a valid username by trying different values until the incorrect password message is returned. In essence, this makes it easier for an attacker to obtain half of the necessary authentication credentials.

While this type of information may be helpful to a user, it is also useful to a potential attacker. In the above example, the message for both failed cases should be the same, such as:

(result)
 
"Login Failed - incorrect username or password"

Example 2

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

(bad code)
Example Language: PHP 
try {
openDbConnection();
}
//print exception message that includes exception message and configuration file location
catch (Exception $e) {
echo 'Caught exception: ', $e->getMessage(), '\n';
echo 'Check credentials in config file at: ', $Mysql_config_location, '\n';
}

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


Example 3

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

(bad code)
Example Language: Java 
public BankAccount getUserBankAccount(String username, String accountNumber) {
BankAccount userAccount = null;
String query = null;
try {
if (isAuthorizedUser(username)) {
query = "SELECT * FROM accounts WHERE owner = "
+ username + " AND accountID = " + accountNumber;
DatabaseManager dbManager = new DatabaseManager();
Connection conn = dbManager.getConnection();
Statement stmt = conn.createStatement();
ResultSet queryResult = stmt.executeQuery(query);
userAccount = (BankAccount)queryResult.getObject(accountNumber);
}
} catch (SQLException ex) {
String logMessage = "Unable to retrieve account information from database,\nquery: " + query;
Logger.getLogger(BankManager.class.getName()).log(Level.SEVERE, logMessage, ex);
}
return userAccount;
}

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


Example 4

This code stores location information about the current user:

(bad code)
Example Language: Java 
locationClient = new LocationClient(this, this, this);
locationClient.connect();
currentUser.setLocation(locationClient.getLastLocation());
...

catch (Exception e) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Sorry, this application has experienced an error.");
AlertDialog alert = builder.create();
alert.show();
Log.e("ExampleActivity", "Caught exception: " + e + " While on User:" + User.toString());
}

When the application encounters an exception it will write the user object to the log. Because the user object contains location information, the user's location is also written to the log.


Example 5

The following is an actual MySQL error statement:

(result)
Example Language: SQL 
Warning: mysql_pconnect(): Access denied for user: 'root@localhost' (Using password: N1nj4) in /usr/local/www/wi-data/includes/database.inc on line 4

The error clearly exposes the database credentials.


Example 6

This code displays some information on a web page.

(bad code)
Example Language: JSP 
Social Security Number: <%= ssn %></br>Credit Card Number: <%= ccn %>

The code displays a user's credit card and social security numbers, even though they aren't absolutely necessary.


Example 7

The following program changes its behavior based on a debug flag.

(bad code)
Example Language: JSP 
<% if (Boolean.getBoolean("debugEnabled")) {
%>
User account number: <%= acctNo %>
<%
} %>

The code writes sensitive debug information to the client browser if the "debugEnabled" flag is set to true .


Example 8

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

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

(bad code)
Example Language: XML 
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

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

(bad code)
Example Language: Java 
locationClient = new LocationClient(this, this, this);
locationClient.connect();
Location userCurrLocation;
userCurrLocation = locationClient.getLastLocation();
deriveStateFromCoords(userCurrLocation);

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


+ Observed Examples
Reference Description
Rust library leaks Oauth client details in application debug logs
Digital Rights Management (DRM) capability for mobile platform leaks pointer information, simplifying ASLR bypass
Enumeration of valid usernames based on inconsistent responses
Account number enumeration via inconsistent responses.
User enumeration via discrepancies in error messages.
Telnet protocol allows servers to obtain sensitive environment information from clients.
Script calls phpinfo(), revealing system configuration to web user
Product sets a different TTL when a port is being filtered than when it is not being filtered, which allows remote attackers to identify filtered ports by comparing TTLs.
Version control system allows remote attackers to determine the existence of arbitrary files and directories via the -X command for an alternate history file, which causes different error messages to be returned.
Virtual machine allows malicious web site operators to determine the existence of files on the client by measuring delays in the execution of the getSystemResource method.
Product immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.
POP3 server reveals a password in an error message after multiple APOP commands are sent. Might be resultant from another weakness.
Program reveals password in error message if attacker can trigger certain database errors.
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).
Direct request to library file in web application triggers pathname leak in error message.
Malformed regexp syntax leads to information exposure in error message.
Password exposed in debug information.
FTP client with debug option enabled shows password to the screen.
Collaboration platform does not clear team emails in a response, allowing leak of email addresses
+ Weakness Ordinalities
Ordinality Description
Primary
(where the weakness exists independent of other weaknesses)
Developers may insert sensitive information that they do not believe, or they might forget to remove the sensitive information after it has been processed
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Separate mistakes or weaknesses could inadvertently make the sensitive information available to an attacker, such as in a detailed error message that can be read by an unauthorized party
+ Detection Methods

Automated Static Analysis - Binary or Bytecode

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

Cost effective for partial coverage:
  • Bytecode Weakness Analysis - including disassembler + source code weakness analysis
  • Inter-application Flow Analysis

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

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

Highly cost effective:
  • Web Application Scanner
  • Web Services Scanner
  • Database Scanners

Effectiveness: High

Dynamic Analysis with Manual Results Interpretation

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

Cost effective for partial coverage:
  • Fuzz Tester
  • Framework-based Fuzzer
  • Automated Monitored Execution
  • Monitored Virtual Environment - run potentially malicious code in sandbox / wrapper / virtual machine, see if it does anything suspicious

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

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

Highly cost effective:
  • Manual Source Code Review (not inspections)

Effectiveness: High

Automated Static Analysis - Source Code

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

Highly cost effective:
  • Context-configured Source Code Weakness Analyzer
Cost effective for partial coverage:
  • Source code Weakness Analyzer

Effectiveness: High

Architecture or Design Review

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

Highly cost effective:
  • Formal Methods / Correct-By-Construction
Cost effective for partial coverage:
  • Attack Modeling
  • Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)

Effectiveness: High

+ Memberships
Section HelpThis 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 ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 635 Weaknesses Originally Used by NVD from 2008 to 2016
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 717 OWASP Top Ten 2007 Category A6 - Information Leakage and Improper Error Handling
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 963 SFP Secondary Cluster: Exposed Data
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1200 Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1337 Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1345 OWASP Top Ten 2021 Category A01:2021 - Broken Access Control
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1350 Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1417 Comprehensive Categorization: Sensitive Information Exposure
MemberOf ViewView - 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). 1430 Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses
+ Vulnerability Mapping Notes

Usage: DISCOURAGED

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

Reason: Frequent Misuse

Rationale:

CWE-200 is commonly misused to represent the loss of confidentiality in a vulnerability, but confidentiality loss is a technical impact - not a root cause error. As of CWE 4.9, over 400 CWE entries can lead to a loss of confidentiality. Other options are often available. [REF-1287].

Comments:

If an error or mistake causes information to be disclosed, then use the CWE ID for that error. Consider starting with improper authorization (CWE-285), insecure permissions (CWE-732), improper authentication (CWE-287), etc. Also consider children such as Insertion of Sensitive Information Into Sent Data (CWE-201), Observable Discrepancy (CWE-203), Insertion of Sensitive Information into Externally-Accessible File or Directory (CWE-538), or others.
+ Notes

Maintenance

As a result of mapping analysis in the 2020 Top 25 and more recent versions, this weakness is under review, since it is frequently misused in mapping to cover many problems that lead to loss of confidentiality. See Mapping Notes, Extended Description, and Alternate Terms.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
PLOVER Information Leak (information disclosure)
OWASP Top Ten 2007 A6 CWE More Specific Information Leakage and Improper Error Handling
WASC 13 Information Leakage
+ References
[REF-172] Chris Wysopal. "Mobile App Top 10 List". 2010-12-13. <https://www.veracode.com/blog/2010/12/mobile-app-top-10-list>. URL validated: 2023-04-07.
[REF-1287] MITRE. "Supplemental Details - 2022 CWE Top 25". Details of Problematic Mappings. 2022-06-28. <https://cwe.mitre.org/top25/archive/2022/2022_cwe_top25_supplemental.html#problematicMappingDetails>. URL validated: 2024-11-17.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
PLOVER
+ Contributions
Contribution Date Contributor Organization
2022-07-11 Nick Johnston
Identified incorrect language tag in demonstrative example.
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Time_of_Introduction
2008-09-08 CWE Content Team MITRE
updated Likelihood_of_Exploit, Relationships, Taxonomy_Mappings, Weakness_Ordinalities
2008-10-14 CWE Content Team MITRE
updated Description
2009-12-28 CWE Content Team MITRE
updated Alternate_Terms, Description, Name
2010-02-16 CWE Content Team MITRE
updated Taxonomy_Mappings
2010-04-05 CWE Content Team MITRE
updated Related_Attack_Patterns
2011-03-29 CWE Content Team MITRE
updated Description, Relationships
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated Related_Attack_Patterns, Relationships
2012-10-30 CWE Content Team MITRE
updated Potential_Mitigations
2013-02-21 CWE Content Team MITRE
updated Alternate_Terms, Applicable_Platforms, References
2014-06-23 CWE Content Team MITRE
updated Related_Attack_Patterns
2014-07-30 CWE Content Team MITRE
updated Detection_Factors, Relationships
2015-12-07 CWE Content Team MITRE
updated Relationships
2017-05-03 CWE Content Team MITRE
updated Related_Attack_Patterns
2017-11-08 CWE Content Team MITRE
updated References
2019-01-03 CWE Content Team MITRE
updated Related_Attack_Patterns
2019-06-20 CWE Content Team MITRE
updated Related_Attack_Patterns, Relationships
2019-09-19 CWE Content Team MITRE
updated Demonstrative_Examples, Observed_Examples, Relationships
2020-02-24 CWE Content Team MITRE
updated Applicable_Platforms, Demonstrative_Examples, Description, Name, Observed_Examples, Related_Attack_Patterns, Relationships, Weakness_Ordinalities
2020-06-25 CWE Content Team MITRE
updated Relationships
2020-08-20 CWE Content Team MITRE
updated Alternate_Terms, Description, Maintenance_Notes, Related_Attack_Patterns, Relationships
2020-12-10 CWE Content Team MITRE
updated Potential_Mitigations
2021-07-20 CWE Content Team MITRE
updated Relationships
2021-10-28 CWE Content Team MITRE
updated Relationships
2022-10-13 CWE Content Team MITRE
updated Demonstrative_Examples, Maintenance_Notes, Observed_Examples, References
2023-04-27 CWE Content Team MITRE
updated References, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
2023-10-26 CWE Content Team MITRE
updated Observed_Examples
2024-11-19
(CWE 4.16, 2024-11-19)
CWE Content Team MITRE
updated Relationships
+ Previous Entry Names
Change Date Previous Entry Name
2009-12-28 Information Leak (Information Disclosure)
2020-02-24 Information Exposure

CWE-287: Improper Authentication

Weakness ID: 287
Vulnerability Mapping: DISCOURAGED This CWE ID should not be used to map to real-world vulnerabilities
Abstraction: Class 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.
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+ Description
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Diagram for CWE-287
+ Alternate Terms
authentification:
An alternate term is "authentification", which appears to be most commonly used by people from non-English-speaking countries.
AuthN:
"AuthN" is typically used as an abbreviation of "authentication" within the web application security community. It is also distinct from "AuthZ," which is an abbreviation of "authorization." The use of "Auth" as an abbreviation is discouraged, since it could be used for either authentication or authorization.
AuthC:
"AuthC" is used as an abbreviation of "authentication," but it appears to used less frequently than "AuthN."
+ Common Consequences
Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Scope Impact Likelihood
Integrity
Confidentiality
Availability
Access Control

Technical Impact: Read Application Data; Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands

This weakness can lead to the exposure of resources or functionality to unintended actors, possibly providing attackers with sensitive information or even execute arbitrary code.
+ Potential Mitigations

Phase: Architecture and Design

Strategy: Libraries or Frameworks

Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
+ Relationships
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Research Concepts" (CWE-1000)
Nature Type ID Name
ChildOf Pillar 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. 284 Improper Access Control
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 295 Improper Certificate Validation
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 306 Missing Authentication for Critical Function
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 645 Overly Restrictive Account Lockout Mechanism
ParentOf Class 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. 1390 Weak Authentication
CanFollow Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 613 Insufficient Session Expiration
Section Help 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 "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
Nature Type ID Name
MemberOf View View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1003 Weaknesses for Simplified Mapping of Published Vulnerabilities
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 290 Authentication Bypass by Spoofing
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 294 Authentication Bypass by Capture-replay
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 295 Improper Certificate Validation
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 306 Missing Authentication for Critical Function
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 307 Improper Restriction of Excessive Authentication Attempts
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 521 Weak Password Requirements
ParentOf Class 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. 522 Insufficiently Protected Credentials
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 640 Weak Password Recovery Mechanism for Forgotten Password
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 798 Use of Hard-coded Credentials
Section Help 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 "Architectural Concepts" (CWE-1008)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1010 Authenticate Actors
Section Help 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 "CISQ Data Protection Measures" (CWE-1340)
Nature Type ID Name
ChildOf Pillar 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. 284 Improper Access Control
+ Modes Of Introduction
Section HelpThe 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
Section HelpThis 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: ICS/OT (Often Prevalent)

+ Likelihood Of Exploit
High
+ Demonstrative Examples

Example 1

The following code intends to ensure that the user is already logged in. If not, the code performs authentication with the user-provided username and password. If successful, it sets the loggedin and user cookies to "remember" that the user has already logged in. Finally, the code performs administrator tasks if the logged-in user has the "Administrator" username, as recorded in the user cookie.

(bad code)
Example Language: Perl 
my $q = new CGI;

if ($q->cookie('loggedin') ne "true") {
if (! AuthenticateUser($q->param('username'), $q->param('password'))) {
ExitError("Error: you need to log in first");
}
else {
# Set loggedin and user cookies.
$q->cookie(
-name => 'loggedin',
-value => 'true'
);

$q->cookie(
-name => 'user',
-value => $q->param('username')
);
}
}

if ($q->cookie('user') eq "Administrator") {
DoAdministratorTasks();
}

Unfortunately, this code can be bypassed. The attacker can set the cookies independently so that the code does not check the username and password. The attacker could do this with an HTTP request containing headers such as:

(attack code)
 
GET /cgi-bin/vulnerable.cgi HTTP/1.1
Cookie: user=Administrator
Cookie: loggedin=true

[body of request]

By setting the loggedin cookie to "true", the attacker bypasses the entire authentication check. By using the "Administrator" value in the user cookie, the attacker also gains privileges to administer the software.


Example 2

In January 2009, an attacker was able to gain administrator access to a Twitter server because the server did not restrict the number of login attempts [REF-236]. The attacker targeted a member of Twitter's support team and was able to successfully guess the member's password using a brute force attack by guessing a large number of common words. After gaining access as the member of the support staff, the attacker used the administrator panel to gain access to 33 accounts that belonged to celebrities and politicians. Ultimately, fake Twitter messages were sent that appeared to come from the compromised accounts.

Example 2 References:
[REF-236] Kim Zetter. "Weak Password Brings 'Happiness' to Twitter Hacker". 2009-01-09. <https://www.wired.com/2009/01/professed-twitt/>. URL validated: 2023-04-07.

Example 3

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

Multiple vendors did not use any authentication or used client-side authentication for critical functionality in their OT products.


+ Observed Examples
Reference Description
Chat application skips validation when Central Authentication Service (CAS) is enabled, effectively removing the second factor from two-factor authentication
Python-based authentication proxy does not enforce password authentication during the initial handshake, allowing the client to bypass authentication by specifying a 'None' authentication type.
Chain: Web UI for a Python RPC framework does not use regex anchors to validate user login emails (CWE-777), potentially allowing bypass of OAuth (CWE-1390).
TCP-based protocol in Programmable Logic Controller (PLC) has no authentication.
Condition Monitor uses a protocol that does not require authentication.
Safety Instrumented System uses proprietary TCP protocols with no authentication.
Distributed Control System (DCS) uses a protocol that has no authentication.
SCADA system only uses client-side authentication, allowing adversaries to impersonate other users.
Chain: Python-based HTTP Proxy server uses the wrong boolean operators (CWE-480) causing an incorrect comparison (CWE-697) that identifies an authN failure if all three conditions are met instead of only one, allowing bypass of the proxy authentication (CWE-1390)
Chain: Cloud computing virtualization platform does not require authentication for upload of a tar format file (CWE-306), then uses .. path traversal sequences (CWE-23) in the file to access unexpected files, as exploited in the wild per CISA KEV.
IT management product does not perform authentication for some REST API requests, as exploited in the wild per CISA KEV.
Firmware for a WiFi router uses a hard-coded password for a BusyBox shell, allowing bypass of authentication through the UART port
Bluetooth speaker does not require authentication for the debug functionality on the UART port, allowing root shell access
Default setting in workflow management product allows all API requests without authentication, as exploited in the wild per CISA KEV.
Stack-based buffer overflows in SFK for wifi chipset used for IoT/embedded devices, as exploited in the wild per CISA KEV.
Mail server does not properly check an access token before executing a Powershell command, as exploited in the wild per CISA KEV.
Chain: user is not prompted for a second authentication factor (CWE-287) when changing the case of their username (CWE-178), as exploited in the wild per CISA KEV.
Authentication bypass by appending specific parameters and values to a URI, as exploited in the wild per CISA KEV.
Mail server does not generate a unique key during installation, as exploited in the wild per CISA KEV.
LDAP Go package allows authentication bypass using an empty password, causing an unauthenticated LDAP bind
login script for guestbook allows bypassing authentication by setting a "login_ok" parameter to 1.
admin script allows authentication bypass by setting a cookie value to "LOGGEDIN".
VOIP product allows authentication bypass using 127.0.0.1 in the Host header.
product uses default "Allow" action, instead of default deny, leading to authentication bypass.
chain: redirect without exit (CWE-698) leads to resultant authentication bypass.
product does not restrict access to a listening port for a critical service, allowing authentication to be bypassed.
product does not properly implement a security-related configuration setting, allowing authentication bypass.
authentication routine returns "nil" instead of "false" in some situations, allowing authentication bypass using an invalid username.
authentication update script does not properly handle when admin does not select any authentication modules, allowing authentication bypass.
use of LDAP authentication with anonymous binds causes empty password to result in successful authentication
product authentication succeeds if user-provided MD5 hash matches the hash in its database; this can be subjected to replay attacks.
chain: product generates predictable MD5 hashes using a constant value combined with username, allowing authentication bypass.
+ Detection Methods

Automated Static Analysis

Automated static analysis is useful for detecting certain types of authentication. A tool may be able to analyze related configuration files, such as .htaccess in Apache web servers, or detect the usage of commonly-used authentication libraries.

Generally, automated static analysis tools have difficulty detecting custom authentication schemes. In addition, the software's design may include some functionality that is accessible to any user and does not require an established identity; an automated technique that detects the absence of authentication may report false positives.

Effectiveness: Limited

Manual Static Analysis

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

Manual static analysis is useful for evaluating the correctness of custom authentication mechanisms.

Effectiveness: High

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

Manual Static Analysis - Binary or Bytecode

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

Cost effective for partial coverage:
  • Binary / Bytecode disassembler - then use manual analysis for vulnerabilities & anomalies

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

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

Cost effective for partial coverage:
  • Web Application Scanner
  • Web Services Scanner
  • Database Scanners

Effectiveness: SOAR Partial

Dynamic Analysis with Manual Results Interpretation

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

Cost effective for partial coverage:
  • Fuzz Tester
  • Framework-based Fuzzer

Effectiveness: SOAR Partial

Manual Static Analysis - Source Code

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

Cost effective for partial coverage:
  • Manual Source Code Review (not inspections)

Effectiveness: SOAR Partial

Automated Static Analysis - Source Code

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

Cost effective for partial coverage:
  • Source code Weakness Analyzer
  • Context-configured Source Code Weakness Analyzer

Effectiveness: SOAR Partial

Automated Static Analysis

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

Cost effective for partial coverage:
  • Configuration Checker

Effectiveness: SOAR Partial

Architecture or Design Review

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

Highly cost effective:
  • Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)
  • Formal Methods / Correct-By-Construction

Effectiveness: High

+ Functional Areas
  • Authentication
+ Memberships
Section HelpThis 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 ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 635 Weaknesses Originally Used by NVD from 2008 to 2016
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 718 OWASP Top Ten 2007 Category A7 - Broken Authentication and Session Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 724 OWASP Top Ten 2004 Category A3 - Broken Authentication and Session Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 812 OWASP Top Ten 2010 Category A3 - Broken Authentication and Session Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 930 OWASP Top Ten 2013 Category A2 - Broken Authentication and Session Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 947 SFP Secondary Cluster: Authentication Bypass
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1028 OWASP Top Ten 2017 Category A2 - Broken Authentication
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1200 Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1337 Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1350 Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1353 OWASP Top Ten 2021 Category A07:2021 - Identification and Authentication Failures
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1364 ICS Communications: Zone Boundary Failures
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1368 ICS Dependencies (& Architecture): External Digital Systems
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1387 Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1396 Comprehensive Categorization: Access Control
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1425 Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf ViewView - 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). 1430 Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses
+ Vulnerability Mapping Notes

Usage: DISCOURAGED

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

Reason: Frequent Misuse

Rationale:

This CWE entry might be misused when lower-level CWE entries are likely to be applicable. It is a level-1 Class (i.e., a child of a Pillar).

Comments:

Consider children or descendants, beginning with CWE-1390: Weak Authentication or CWE-306: Missing Authentication for Critical Function.
Suggestions:
CWE-ID Comment
CWE-1390 Weak Authentication
CWE-306 Missing Authentication for Critical Function
+ Notes

Relationship

This can be resultant from SQL injection vulnerabilities and other issues.

Maintenance

The Taxonomy_Mappings to ISA/IEC 62443 were added in CWE 4.10, but they are still under review and might change in future CWE versions. These draft mappings were performed by members of the "Mapping CWE to 62443" subgroup of the CWE-CAPEC ICS/OT Special Interest Group (SIG), and their work is incomplete as of CWE 4.10. The mappings are included to facilitate discussion and review by the broader ICS/OT community, and they are likely to change in future CWE versions.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
PLOVER Authentication Error
OWASP Top Ten 2007 A7 CWE More Specific Broken Authentication and Session Management
OWASP Top Ten 2004 A3 CWE More Specific Broken Authentication and Session Management
WASC 1 Insufficient Authentication
ISA/IEC 62443 Part 3-3 Req SR 1.1
ISA/IEC 62443 Part 3-3 Req SR 1.2
ISA/IEC 62443 Part 4-2 Req CR 1.1
ISA/IEC 62443 Part 4-2 Req CR 1.2
+ References
[REF-236] Kim Zetter. "Weak Password Brings 'Happiness' to Twitter Hacker". 2009-01-09. <https://www.wired.com/2009/01/professed-twitt/>. URL validated: 2023-04-07.
[REF-237] OWASP. "Top 10 2007-Broken Authentication and Session Management". 2007. <http://www.owasp.org/index.php/Top_10_2007-A7>.
[REF-238] OWASP. "Guide to Authentication". <http://www.owasp.org/index.php/Guide_to_Authentication>.
[REF-239] Microsoft. "Authentication". <http://msdn.microsoft.com/en-us/library/aa374735(VS.85).aspx>.
[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 4, "Authentication" Page 109. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.
[REF-1283] Forescout Vedere Labs. "OT:ICEFALL: The legacy of "insecure by design" and its implications for certifications and risk management". 2022-06-20. <https://www.forescout.com/resources/ot-icefall-report/>.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
PLOVER
+ Contributions
Contribution Date Contributor Organization
2024-02-29
(CWE 4.15, 2024-07-16)
Abhi Balakrishnan
Provided diagram to improve CWE usability
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Time_of_Introduction
2008-08-15 Veracode
Suggested OWASP Top Ten 2004 mapping
2008-09-08 CWE Content Team MITRE
updated Alternate_Terms, Common_Consequences, Relationships, Relationship_Notes, Taxonomy_Mappings
2008-10-14 CWE Content Team MITRE
updated Relationships
2009-01-12 CWE Content Team MITRE
updated Name
2009-05-27 CWE Content Team MITRE
updated Description, Related_Attack_Patterns
2009-07-27 CWE Content Team MITRE
updated Relationships
2009-10-29 CWE Content Team MITRE
updated Common_Consequences, Observed_Examples
2009-12-28 CWE Content Team MITRE
updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Detection_Factors, Likelihood_of_Exploit, References
2010-02-16 CWE Content Team MITRE
updated Alternate_Terms, Detection_Factors, Potential_Mitigations, References, Relationships, Taxonomy_Mappings
2010-06-21 CWE Content Team MITRE
updated Relationships
2011-03-29 CWE Content Team MITRE
updated Relationships
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated Relationships
2013-07-17 CWE Content Team MITRE
updated Relationships
2014-02-18 CWE Content Team MITRE
updated Relationships
2014-06-23 CWE Content Team MITRE
updated Relationships
2014-07-30 CWE Content Team MITRE
updated Detection_Factors, Relationships
2015-12-07 CWE Content Team MITRE
updated Relationships
2017-01-19 CWE Content Team MITRE
updated Relationships
2017-05-03 CWE Content Team MITRE
updated Related_Attack_Patterns, Relationships
2017-11-08 CWE Content Team MITRE
updated Demonstrative_Examples, Likelihood_of_Exploit, Modes_of_Introduction, References, Relationships
2018-03-27 CWE Content Team MITRE
updated References, Relationships
2019-01-03 CWE Content Team MITRE
updated Related_Attack_Patterns
2019-06-20 CWE Content Team MITRE
updated Demonstrative_Examples, Related_Attack_Patterns, Relationships
2019-09-19 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated Relationships
2020-08-20 CWE Content Team MITRE
updated Relationships
2020-12-10 CWE Content Team MITRE
updated Relationships
2021-03-15 CWE Content Team MITRE
updated Alternate_Terms, Demonstrative_Examples
2021-07-20 CWE Content Team MITRE
updated Relationships
2021-10-28 CWE Content Team MITRE
updated Relationships
2022-06-28 CWE Content Team MITRE
updated Observed_Examples, Relationships
2022-10-13 CWE Content Team MITRE
updated Applicable_Platforms, Demonstrative_Examples, Observed_Examples, References, Relationships
2023-01-31 CWE Content Team MITRE
updated Description, Maintenance_Notes, Observed_Examples, Taxonomy_Mappings
2023-04-27 CWE Content Team MITRE
updated Demonstrative_Examples, References, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes, Relationships
2023-10-26 CWE Content Team MITRE
updated Observed_Examples
2024-02-29
(CWE 4.14, 2024-02-29)
CWE Content Team MITRE
updated Observed_Examples
2024-07-16
(CWE 4.15, 2024-07-16)
CWE Content Team MITRE
updated Diagram
2024-11-19
(CWE 4.16, 2024-11-19)
CWE Content Team MITRE
updated Relationships
+ Previous Entry Names
Change Date Previous Entry Name
2008-04-11 Authentication Issues
2009-01-12 Insufficient Authentication

CWE-94: Improper Control of Generation of Code ('Code Injection')

Weakness ID: 94
Vulnerability Mapping: ALLOWED This CWE ID could be used to map to real-world vulnerabilities in limited situations requiring careful review (with careful review of mapping notes)
Abstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
+ Extended Description

When a product allows a user's input to contain code syntax, it might be possible for an attacker to craft the code in such a way that it will alter the intended control flow of the product. Such an alteration could lead to arbitrary code execution.

Injection problems encompass a wide variety of issues -- all mitigated in very different ways. For this reason, the most effective way to discuss these weaknesses is to note the distinct features which classify them as injection weaknesses. The most important issue to note is that all injection problems share one thing in common -- i.e., they allow for the injection of control plane data into the user-controlled data plane. This means that the execution of the process may be altered by sending code in through legitimate data channels, using no other mechanism. While buffer overflows, and many other flaws, involve the use of some further issue to gain execution, injection problems need only for the data to be parsed. The most classic instantiations of this category of weakness are SQL injection and format string vulnerabilities.

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

Technical Impact: Bypass Protection Mechanism

In some cases, injectable code controls authentication; this may lead to a remote vulnerability.
Access Control

Technical Impact: Gain Privileges or Assume Identity

Injected code can access resources that the attacker is directly prevented from accessing.
Integrity
Confidentiality
Availability

Technical Impact: Execute Unauthorized Code or Commands

Code injection attacks can lead to loss of data integrity in nearly all cases as the control-plane data injected is always incidental to data recall or writing. Additionally, code injection can often result in the execution of arbitrary code.
Non-Repudiation

Technical Impact: Hide Activities

Often the actions performed by injected control code are unlogged.
+ Potential Mitigations

Phase: Architecture and Design

Refactor your program so that you do not have to dynamically generate code.

Phase: Architecture and Design

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 which code can be executed by your product.

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.

Phase: Implementation

Strategy: Input Validation

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

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

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

To reduce the likelihood of code injection, use stringent allowlists that limit which constructs are allowed. If you are dynamically constructing code that invokes a function, then verifying that the input is alphanumeric might be insufficient. An attacker might still be able to reference a dangerous function that you did not intend to allow, such as system(), exec(), or exit().

Phase: Testing

Use automated static analysis tools that target this type of weakness. Many modern techniques use data flow analysis to minimize the number of false positives. This is not a perfect solution, since 100% accuracy and coverage are not feasible.

Phase: Testing

Use 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.

Phase: Operation

Strategy: Compilation or Build Hardening

Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).

Phase: Operation

Strategy: Environment Hardening

Run the code in an environment that performs automatic taint propagation and prevents any command execution that uses tainted variables, such as Perl's "-T" switch. This will force the program to perform validation steps that remove the taint, although you must be careful to correctly validate your inputs so that you do not accidentally mark dangerous inputs as untainted (see CWE-183 and CWE-184).

Phase: Implementation

For Python programs, it is frequently encouraged to use the ast.literal_eval() function instead of eval, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].

Effectiveness: Discouraged Common Practice

+ Relationships
Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
+ Relevant to the view "Research Concepts" (CWE-1000)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 913 Improper Control of Dynamically-Managed Code Resources
ParentOf Variant 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. 95 Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 96 Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection')
ParentOf Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. 1336 Improper Neutralization of Special Elements Used in a Template Engine
CanFollow Variant 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. 98 Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion')
Section Help 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 "Software Development" (CWE-699)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 137 Data Neutralization Issues
Section Help 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 "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
Nature Type ID Name
ChildOf Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. 74 Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Section Help 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 "Architectural Concepts" (CWE-1008)
Nature Type ID Name
MemberOf Category Category - a CWE entry that contains a set of other entries that share a common characteristic. 1019 Validate Inputs
+ Modes Of Introduction
Section HelpThe 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
Section HelpThis 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: Interpreted (Sometimes Prevalent)

Technologies

AI/ML (Undetermined Prevalence)

+ Likelihood Of Exploit
Medium
+ Demonstrative Examples

Example 1

This example attempts to write user messages to a message file and allow users to view them.

(bad code)
Example Language: PHP 
$MessageFile = "messages.out";
if ($_GET["action"] == "NewMessage") {
$name = $_GET["name"];
$message = $_GET["message"];
$handle = fopen($MessageFile, "a+");
fwrite($handle, "<b>$name</b> says '$message'<hr>\n");
fclose($handle);
echo "Message Saved!<p>\n";
}
else if ($_GET["action"] == "ViewMessages") {
include($MessageFile);
}

While the programmer intends for the MessageFile to only include data, an attacker can provide a message such as:

(attack code)
 
name=h4x0r
message=%3C?php%20system(%22/bin/ls%20-l%22);?%3E

which will decode to the following:

(attack code)
 
<?php system("/bin/ls -l");?>

The programmer thought they were just including the contents of a regular data file, but PHP parsed it and executed the code. Now, this code is executed any time people view messages.

Notice that XSS (CWE-79) is also possible in this situation.


Example 2

edit-config.pl: This CGI script is used to modify settings in a configuration file.

(bad code)
Example Language: Perl 
use CGI qw(:standard);

sub config_file_add_key {
my ($fname, $key, $arg) = @_;

# code to add a field/key to a file goes here
}

sub config_file_set_key {
my ($fname, $key, $arg) = @_;

# code to set key to a particular file goes here
}

sub config_file_delete_key {
my ($fname, $key, $arg) = @_;

# code to delete key from a particular file goes here
}

sub handleConfigAction {
my ($fname, $action) = @_;
my $key = param('key');
my $val = param('val');

# this is super-efficient code, especially if you have to invoke


# any one of dozens of different functions!

my $code = "config_file_$action_key(\$fname, \$key, \$val);";
eval($code);
}

$configfile = "/home/cwe/config.txt";
print header;
if (defined(param('action'))) {
handleConfigAction($configfile, param('action'));
}
else {
print "No action specified!\n";
}

The script intends to take the 'action' parameter and invoke one of a variety of functions based on the value of that parameter - config_file_add_key(), config_file_set_key(), or config_file_delete_key(). It could set up a conditional to invoke each function separately, but eval() is a powerful way of doing the same thing in fewer lines of code, especially when a large number of functions or variables are involved. Unfortunately, in this case, the attacker can provide other values in the action parameter, such as:

(attack code)
 
add_key(",","); system("/bin/ls");

This would produce the following string in handleConfigAction():

(result)
 
config_file_add_key(",","); system("/bin/ls");

Any arbitrary Perl code could be added after the attacker has "closed off" the construction of the original function call, in order to prevent parsing errors from causing the malicious eval() to fail before the attacker's payload is activated. This particular manipulation would fail after the system() call, because the "_key(\$fname, \$key, \$val)" portion of the string would cause an error, but this is irrelevant to the attack because the payload has already been activated.


Example 3

This simple script asks a user to supply a list of numbers as input and adds them together.

(bad code)
Example Language: Python 
def main():
sum = 0
numbers = eval(input("Enter a space-separated list of numbers: "))
for num in numbers:
sum = sum + num
print(f"Sum of {numbers} = {sum}")
main()

The eval() function can take the user-supplied list and convert it into a Python list object, therefore allowing the programmer to use list comprehension methods to work with the data. However, if code is supplied to the eval() function, it will execute that code. For example, a malicious user could supply the following string:

(attack code)
 
__import__('subprocess').getoutput('rm -r *')

This would delete all the files in the current directory. For this reason, it is not recommended to use eval() with untrusted input.

A way to accomplish this without the use of eval() is to apply an integer conversion on the input within a try/except block. If the user-supplied input is not numeric, this will raise a ValueError. By avoiding eval(), there is no opportunity for the input string to be executed as code.

(good code)
Example Language: Python 
def main():
sum = 0
numbers = input("Enter a space-separated list of numbers: ").split(" ")
try:
for num in numbers:
sum = sum + int(num)
print(f"Sum of {numbers} = {sum}")
except ValueError:
print("Error: invalid input")
main()

An alternative, commonly-cited mitigation for this kind of weakness is to use the ast.literal_eval() function, since it is intentionally designed to avoid executing code. However, an adversary could still cause excessive memory or stack consumption via deeply nested structures [REF-1372], so the python documentation discourages use of ast.literal_eval() on untrusted data [REF-1373].


+ Observed Examples
Reference Description
Math component in an LLM framework translates user input into a Python expression that is input into the Python exec() method, allowing code execution - one variant of a "prompt injection" attack.
Python-based library uses an LLM prompt containing user input to dynamically generate code that is then fed as input into the Python exec() method, allowing code execution - one variant of a "prompt injection" attack.
Framework for LLM applications allows eval injection via a crafted response from a hosting provider.
Python compiler uses eval() to execute malicious strings as Python code.
Chain: regex in EXIF processor code does not correctly determine where a string ends (CWE-625), enabling eval injection (CWE-95), as exploited in the wild per CISA KEV.
"Code injection" in VPN product, as exploited in the wild per CISA KEV.
Eval injection in PHP program.
Eval injection in Perl program.
Eval injection in Perl program using an ID that should only contain hyphens and numbers.
Direct code injection into Perl eval function.
Eval injection in Perl program.
Direct code injection into Perl eval function.
Direct code injection into Perl eval function.
MFV. code injection into PHP eval statement using nested constructs that should not be nested.
MFV. code injection into PHP eval statement using nested constructs that should not be nested.
Code injection into Python eval statement from a field in a formatted file.
Eval injection in Python program.
chain: Resultant eval injection. An invalid value prevents initialization of variables, which can be modified by attacker and later injected into PHP eval statement.
Perl code directly injected into CGI library file from parameters to another CGI program.
Direct PHP code injection into supporting template file.
Direct code injection into PHP script that can be accessed by attacker.
PHP code from User-Agent HTTP header directly inserted into log file implemented as PHP script.
+ Detection Methods

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
Section HelpThis 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 ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 635 Weaknesses Originally Used by NVD from 2008 to 2016
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 752 2009 Top 25 - Risky Resource Management
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 884 CWE Cross-section
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 991 SFP Secondary Cluster: Tainted Input to Environment
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1200 Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1347 OWASP Top Ten 2021 Category A03:2021 - Injection
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1350 Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1387 Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1409 Comprehensive Categorization: Injection
MemberOf ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). 1425 Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses
MemberOf ViewView - 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). 1430 Weaknesses in the 2024 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)

Reasons: Frequent Misuse, Frequent Misinterpretation

Rationale:

This entry is frequently misused for vulnerabilities with a technical impact of "code execution," which does not by itself indicate a root cause weakness, since dozens of weaknesses can enable code execution.

Comments:

This weakness only applies when the product's functionality intentionally constructs all or part of a code segment. It could be that executing code could be the result of other weaknesses that do not involve the construction of code segments.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
PLOVER CODE Code Evaluation and Injection
ISA/IEC 62443 Part 4-2 Req CR 3.5
ISA/IEC 62443 Part 3-3 Req SR 3.5
ISA/IEC 62443 Part 4-1 Req SVV-1
ISA/IEC 62443 Part 4-1 Req SVV-3
+ References
[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 3: Web-Client Related Vulnerabilities (XSS)." Page 63. McGraw-Hill. 2010.
[REF-1372] "How ast.literal_eval can cause memory exhaustion". Reddit. 2022-12-14. <https://www.reddit.com/r/learnpython/comments/zmbhcf/how_astliteral_eval_can_cause_memory_exhaustion/>. URL validated: 2023-11-03.
[REF-1373] "ast - Abstract Syntax Trees". ast.literal_eval(node_or_string). Python. 2023-11-02. <https://docs.python.org/3/library/ast.html#ast.literal_eval>. URL validated: 2023-11-03.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
PLOVER
+ Contributions
Contribution Date Contributor Organization
2023-06-29
(CWE 4.12, 2023-06-29)
"Mapping CWE to 62443" Sub-Working Group CWE-CAPEC ICS/OT SIG
Suggested mappings to ISA/IEC 62443.
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Time_of_Introduction
2008-09-08 CWE Content Team MITRE
updated Applicable_Platforms, Relationships, Research_Gaps, Taxonomy_Mappings
2009-01-12 CWE Content Team MITRE
updated Common_Consequences, Demonstrative_Examples, Description, Likelihood_of_Exploit, Name, Potential_Mitigations, Relationships
2009-03-10 CWE Content Team MITRE
updated Potential_Mitigations
2009-05-27 CWE Content Team MITRE
updated Demonstrative_Examples, Name
2010-02-16 CWE Content Team MITRE
updated Potential_Mitigations
2010-06-21 CWE Content Team MITRE
updated Description, Potential_Mitigations
2011-03-29 CWE Content Team MITRE
updated Name
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated Common_Consequences, Demonstrative_Examples, Observed_Examples, References, Relationships
2012-10-30 CWE Content Team MITRE
updated Potential_Mitigations
2013-02-21 CWE Content Team MITRE
updated Relationships
2014-07-30 CWE Content Team MITRE
updated Relationships
2015-12-07 CWE Content Team MITRE
updated Relationships
2017-11-08 CWE Content Team MITRE
updated Demonstrative_Examples, Modes_of_Introduction, Relationships
2019-06-20 CWE Content Team MITRE
updated Related_Attack_Patterns, Type
2019-09-19 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated Potential_Mitigations, Relationships
2020-06-25 CWE Content Team MITRE
updated Potential_Mitigations
2020-08-20 CWE Content Team MITRE
updated Relationships
2021-03-15 CWE Content Team MITRE
updated Demonstrative_Examples
2021-07-20 CWE Content Team MITRE
updated Relationships
2021-10-28 CWE Content Team MITRE
updated Relationships
2022-04-28 CWE Content Team MITRE
updated Research_Gaps
2022-06-28 CWE Content Team MITRE
updated Observed_Examples, Relationships
2022-10-13 CWE Content Team MITRE
updated Observed_Examples
2023-01-31 CWE Content Team MITRE
updated Demonstrative_Examples, Description, Potential_Mitigations, Relationships
2023-04-27 CWE Content Team MITRE
updated Demonstrative_Examples, Detection_Factors, Relationships, Time_of_Introduction
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes, Relationships, Taxonomy_Mappings
2024-02-29
(CWE 4.14, 2024-02-29)
CWE Content Team MITRE
updated Demonstrative_Examples, Potential_Mitigations, References
2024-07-16
(CWE 4.15, 2024-07-16)
CWE Content Team MITRE
updated Applicable_Platforms, Observed_Examples
2024-11-19
(CWE 4.16, 2024-11-19)
CWE Content Team MITRE
updated Mapping_Notes, Relationships
+ Previous Entry Names
Change Date Previous Entry Name
2009-01-12 Code Injection
2009-05-27 Failure to Control Generation of Code (aka 'Code Injection')
2011-03-29 Failure to Control Generation of Code ('Code Injection')