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Home > CWE List > VIEW SLICE: CWE-1154: Weaknesses Addressed by the SEI CERT C Coding Standard (4.16)  
ID

CWE VIEW: Weaknesses Addressed by the SEI CERT C Coding Standard

View ID: 1154
Vulnerability Mapping: PROHIBITED This CWE ID must not be used to map to real-world vulnerabilities
Type: Graph
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+ Objective
CWE entries in this view (graph) are fully or partially eliminated by following the guidance presented in the online wiki that reflects that current rules and recommendations of the SEI CERT C Coding Standard.
+ Audience
Stakeholder Description
Software Developers By following the SEI CERT C Coding Standard, developers will be able to fully or partially prevent the weaknesses that are identified in this view. In addition, developers can use a CWE coverage graph to determine which weaknesses are not directly addressed by the standard, which will help identify and resolve remaining gaps in training, tool acquisition, or other approaches for reducing weaknesses.
Product Customers If a software developer claims to be following the SEI CERT C Coding standard, then customers can search for the weaknesses in this view in order to formulate independent evidence of that claim.
Educators Educators can use this view in multiple ways. For example, if there is a focus on teaching weaknesses, the educator could link them to the relevant Secure Coding Standard.
+ Relationships
The following graph shows the tree-like relationships between weaknesses that exist at different levels of abstraction. At the highest level, categories and pillars exist to group weaknesses. Categories (which are not technically weaknesses) are special CWE entries used to group weaknesses that share a common characteristic. Pillars are weaknesses that are described in the most abstract fashion. Below these top-level entries are weaknesses are varying levels of abstraction. Classes are still very abstract, typically independent of any specific language or technology. Base level weaknesses are used to present a more specific type of weakness. A variant is a weakness that is described at a very low level of detail, typically limited to a specific language or technology. A chain is a set of weaknesses that must be reachable consecutively in order to produce an exploitable vulnerability. While a composite is a set of weaknesses that must all be present simultaneously in order to produce an exploitable vulnerability.
Show Details:
1154 - Weaknesses Addressed by the SEI CERT C Coding Standard
* Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 01. Preprocessor (PRE) - (1155)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1155 (SEI CERT C Coding Standard - Guidelines 01. Preprocessor (PRE))
Weaknesses in this category are related to the rules and recommendations in the Preprocessor (PRE) section of the SEI CERT C Coding Standard.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 02. Declarations and Initialization (DCL) - (1156)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1156 (SEI CERT C Coding Standard - Guidelines 02. Declarations and Initialization (DCL))
Weaknesses in this category are related to the rules and recommendations in the Declarations and Initialization (DCL) section of the SEI CERT C Coding Standard.
* 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. Return of Stack Variable Address - (562)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1156 (SEI CERT C Coding Standard - Guidelines 02. Declarations and Initialization (DCL)) > 562 (Return of Stack Variable Address)
A function returns the address of a stack variable, which will cause unintended program behavior, typically in the form of a crash.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP) - (1157)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP))
Weaknesses in this category are related to the rules and recommendations in the Expressions (EXP) section of the SEI CERT C Coding Standard.
* 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. Reliance on Undefined, Unspecified, or Implementation-Defined Behavior - (758)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 758 (Reliance on Undefined, Unspecified, or Implementation-Defined Behavior)
The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.
* 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 Uninitialized Resource - (908)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 908 (Use of Uninitialized Resource)
The product uses or accesses a resource that has not been initialized.
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 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
* Chain Chain - a Compound Element that is a sequence of two or more separate weaknesses that can be closely linked together within software. One weakness, X, can directly create the conditions that are necessary to cause another weakness, Y, to enter a vulnerable condition. When this happens, CWE refers to X as "primary" to Y, and Y is "resultant" from X. Chains can involve more than two weaknesses, and in some cases, they might have a tree-like structure. Unchecked Return Value to NULL Pointer Dereference - (690)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 690 (Unchecked Return Value to NULL Pointer Dereference)
The product does not check for an error after calling a function that can return with a NULL pointer if the function fails, which leads to a resultant NULL pointer dereference.
* 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. Function Call with Incorrectly Specified Arguments - (628)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 628 (Function Call with Incorrectly Specified Arguments)
The product calls a function, procedure, or routine with arguments that are not correctly specified, leading to always-incorrect behavior and resultant weaknesses.
* 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. Function Call With Incorrect Number of Arguments - (685)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 685 (Function Call With Incorrect Number of Arguments)
The product calls a function, procedure, or routine, but the caller specifies too many arguments, or too few arguments, which may lead to undefined behavior and resultant weaknesses.
* 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. Function Call With Incorrect Argument Type - (686)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 686 (Function Call With Incorrect Argument Type)
The product calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses.
* 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. Access of Resource Using Incompatible Type ('Type Confusion') - (843)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 843 (Access of Resource Using Incompatible Type ('Type Confusion'))
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type. Object Type Confusion
* 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 Type Conversion or Cast - (704)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 704 (Incorrect Type Conversion or Cast)
The product does not correctly convert an object, resource, or structure from one type to a different type.
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 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. Out-of-bounds Read - (125)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 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. Use of Incorrect Operator - (480)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 480 (Use of Incorrect Operator)
The product accidentally uses the wrong operator, which changes the logic in security-relevant ways.
* 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. Assigning instead of Comparing - (481)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1157 (SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)) > 481 (Assigning instead of Comparing)
The code uses an operator for assignment when the intention was to perform a comparison.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 04. Integers (INT) - (1158)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT))
Weaknesses in this category are related to the rules and recommendations in the Integers (INT) section of the SEI CERT C Coding Standard.
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 190 (Integer Overflow or Wraparound)
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number. Overflow Wraparound wrap, wrap-around, wrap around
* 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. Incorrect Calculation of Buffer Size - (131)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 131 (Incorrect Calculation of Buffer Size)
The product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 Underflow (Wrap or Wraparound) - (191)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 191 (Integer Underflow (Wrap or Wraparound))
The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. Integer underflow
* Chain Chain - a Compound Element that is a sequence of two or more separate weaknesses that can be closely linked together within software. One weakness, X, can directly create the conditions that are necessary to cause another weakness, Y, to enter a vulnerable condition. When this happens, CWE refers to X as "primary" to Y, and Y is "resultant" from X. Chains can involve more than two weaknesses, and in some cases, they might have a tree-like structure. Integer Overflow to Buffer Overflow - (680)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 680 (Integer Overflow to Buffer Overflow)
The product performs a calculation to determine how much memory to allocate, but an integer overflow can occur that causes less memory to be allocated than expected, leading to a buffer overflow.
* 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. Integer Coercion Error - (192)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 192 (Integer Coercion Error)
Integer coercion refers to a set of flaws pertaining to the type casting, extension, or truncation of primitive data types.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Numeric Truncation Error - (197)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 197 (Numeric Truncation Error)
Truncation errors occur when a primitive is cast to a primitive of a smaller size and data is lost in the conversion.
* 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. Incorrect Conversion between Numeric Types - (681)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 681 (Incorrect Conversion between Numeric Types)
When converting from one data type to another, such as long to integer, data can be omitted or translated in a way that produces unexpected values. If the resulting values are used in a sensitive context, then dangerous behaviors may occur.
* 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 Type Conversion or Cast - (704)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 704 (Incorrect Type Conversion or Cast)
The product does not correctly convert an object, resource, or structure from one type to a different type.
* 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. Unexpected Sign Extension - (194)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 194 (Unexpected Sign Extension)
The product performs an operation on a number that causes it to be sign extended when it is transformed into a larger data type. When the original number is negative, this can produce unexpected values that lead to resultant weaknesses.
* 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. Signed to Unsigned Conversion Error - (195)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 195 (Signed to Unsigned Conversion Error)
The product uses a signed primitive and performs a cast to an unsigned primitive, which can produce an unexpected value if the value of the signed primitive can not be represented using an unsigned primitive.
* 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. Divide By Zero - (369)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 369 (Divide By Zero)
The product divides a value by zero.
* 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. Incorrect Calculation - (682)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 682 (Incorrect Calculation)
The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.
* 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. Reliance on Undefined, Unspecified, or Implementation-Defined Behavior - (758)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 758 (Reliance on Undefined, Unspecified, or Implementation-Defined Behavior)
The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.
* 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. Assignment of a Fixed Address to a Pointer - (587)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1158 (SEI CERT C Coding Standard - Guidelines 04. Integers (INT)) > 587 (Assignment of a Fixed Address to a Pointer)
The product sets a pointer to a specific address other than NULL or 0.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 05. Floating Point (FLP) - (1159)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1159 (SEI CERT C Coding Standard - Guidelines 05. Floating Point (FLP))
Weaknesses in this category are related to the rules and recommendations in the Floating Point (FLP) section of the SEI CERT C Coding Standard.
* 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. Incorrect Calculation - (682)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1159 (SEI CERT C Coding Standard - Guidelines 05. Floating Point (FLP)) > 682 (Incorrect Calculation)
The product performs a calculation that generates incorrect or unintended results that are later used in security-critical decisions or resource management.
* 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. Unchecked Error Condition - (391)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1159 (SEI CERT C Coding Standard - Guidelines 05. Floating Point (FLP)) > 391 (Unchecked Error Condition)
[PLANNED FOR DEPRECATION. SEE MAINTENANCE NOTES AND CONSIDER CWE-252, CWE-248, OR CWE-1069.] Ignoring exceptions and other error conditions may allow an attacker to induce unexpected behavior unnoticed.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Incorrect Conversion between Numeric Types - (681)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1159 (SEI CERT C Coding Standard - Guidelines 05. Floating Point (FLP)) > 681 (Incorrect Conversion between Numeric Types)
When converting from one data type to another, such as long to integer, data can be omitted or translated in a way that produces unexpected values. If the resulting values are used in a sensitive context, then dangerous behaviors may occur.
* 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. Numeric Truncation Error - (197)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1159 (SEI CERT C Coding Standard - Guidelines 05. Floating Point (FLP)) > 197 (Numeric Truncation Error)
Truncation errors occur when a primitive is cast to a primitive of a smaller size and data is lost in the conversion.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR) - (1160)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR))
Weaknesses in this category are related to the rules and recommendations in the Arrays (ARR) section of the SEI CERT C Coding Standard.
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. Buffer Overflow buffer overrun memory safety
* 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. Improper Validation of Array Index - (129)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 129 (Improper Validation of Array Index)
The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. out-of-bounds array index index-out-of-range array index underflow
* 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. Access of Memory Location Before Start of Buffer - (786)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 786 (Access of Memory Location Before Start of Buffer)
The product reads or writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer.
* 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. Write-what-where Condition - (123)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 123 (Write-what-where Condition)
Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 125 (Out-of-bounds Read)
The product reads data past the end, or before the beginning, of the intended buffer. OOB read
* 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. Reliance on Undefined, Unspecified, or Implementation-Defined Behavior - (758)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 758 (Reliance on Undefined, Unspecified, or Implementation-Defined Behavior)
The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.
* 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 Pointer Subtraction to Determine Size - (469)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 469 (Use of Pointer Subtraction to Determine Size)
The product subtracts one pointer from another in order to determine size, but this calculation can be incorrect if the pointers do not exist in the same memory chunk.
* 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. Stack-based Buffer Overflow - (121)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 121 (Stack-based Buffer Overflow)
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Stack Overflow
* 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. Buffer Access with Incorrect Length Value - (805)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 805 (Buffer Access with Incorrect Length Value)
The product uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.
* 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. Incorrect Pointer Scaling - (468)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1160 (SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)) > 468 (Incorrect Pointer Scaling)
In C and C++, one may often accidentally refer to the wrong memory due to the semantics of when math operations are implicitly scaled.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR) - (1161)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR))
Weaknesses in this category are related to the rules and recommendations in the Characters and Strings (STR) section of the SEI CERT C Coding Standard.
* 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. Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') - (120)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 120 (Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'))
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. Classic Buffer Overflow Unbounded Transfer
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data. Buffer Overflow buffer overrun memory safety
* 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. Stack-based Buffer Overflow - (121)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 121 (Stack-based Buffer Overflow)
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Stack Overflow
* 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. Heap-based Buffer Overflow - (122)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 122 (Heap-based Buffer Overflow)
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
* 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. Write-what-where Condition - (123)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 123 (Write-what-where Condition)
Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 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. Use of Potentially Dangerous Function - (676)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 676 (Use of Potentially Dangerous Function)
The product invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Improper Null Termination - (170)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 170 (Improper Null Termination)
The product does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator.
* 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 Type Conversion or Cast - (704)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1161 (SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)) > 704 (Incorrect Type Conversion or Cast)
The product does not correctly convert an object, resource, or structure from one type to a different type.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM) - (1162)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM))
Weaknesses in this category are related to the rules and recommendations in the Memory Management (MEM) section of the SEI CERT C Coding Standard.
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 416 (Use After Free)
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. Dangling 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. Operation on a Resource after Expiration or Release - (672)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 672 (Operation on a Resource after Expiration or Release)
The product uses, accesses, or otherwise operates on a resource after that resource has been expired, released, or revoked.
* 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. Reliance on Undefined, Unspecified, or Implementation-Defined Behavior - (758)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 758 (Reliance on Undefined, Unspecified, or Implementation-Defined Behavior)
The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.
* 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. Operation on Resource in Wrong Phase of Lifetime - (666)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 666 (Operation on Resource in Wrong Phase of Lifetime)
The product performs an operation on a resource at the wrong phase of the resource's lifecycle, which can lead to unexpected behaviors.
* 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. Double Free - (415)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 415 (Double Free)
The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. Double-free
* 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. Missing Release of Memory after Effective Lifetime - (401)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 401 (Missing Release of Memory after Effective Lifetime)
The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Memory 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. Improper Resource Shutdown or Release - (404)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 404 (Improper Resource Shutdown or Release)
The product does not release or incorrectly releases a resource before it is made available for re-use.
* 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. Incomplete Cleanup - (459)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 459 (Incomplete Cleanup)
The product does not properly "clean up" and remove temporary or supporting resources after they have been used. Insufficient Cleanup
* 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 Reference to Active Allocated Resource - (771)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 771 (Missing Reference to Active Allocated Resource)
The product does not properly maintain a reference to a resource that has been allocated, which prevents the resource from being reclaimed.
* 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 Release of Resource after Effective Lifetime - (772)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 772 (Missing Release of Resource after Effective Lifetime)
The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.
* 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. Free of Memory not on the Heap - (590)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 590 (Free of Memory not on the Heap)
The product calls free() on a pointer to memory that was not allocated using associated heap allocation functions such as malloc(), calloc(), or realloc().
* 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. Incorrect Calculation of Buffer Size - (131)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 131 (Incorrect Calculation of Buffer Size)
The product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.
* Chain Chain - a Compound Element that is a sequence of two or more separate weaknesses that can be closely linked together within software. One weakness, X, can directly create the conditions that are necessary to cause another weakness, Y, to enter a vulnerable condition. When this happens, CWE refers to X as "primary" to Y, and Y is "resultant" from X. Chains can involve more than two weaknesses, and in some cases, they might have a tree-like structure. Integer Overflow to Buffer Overflow - (680)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 680 (Integer Overflow to Buffer Overflow)
The product performs a calculation to determine how much memory to allocate, but an integer overflow can occur that causes less memory to be allocated than expected, leading to a buffer overflow.
* 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 of sizeof() on a Pointer Type - (467)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 467 (Use of sizeof() on a Pointer Type)
The code calls sizeof() on a pointer type, which can be an incorrect calculation if the programmer intended to determine the size of the data that is being pointed to.
* 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. Memory Allocation with Excessive Size Value - (789)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 789 (Memory Allocation with Excessive Size Value)
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. Stack 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. Integer Overflow or Wraparound - (190)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1162 (SEI CERT C Coding Standard - Guidelines 08. Memory Management (MEM)) > 190 (Integer Overflow or Wraparound)
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number. Overflow Wraparound wrap, wrap-around, wrap around
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO) - (1163)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO))
Weaknesses in this category are related to the rules and recommendations in the Input Output (FIO) section of the SEI CERT C Coding Standard.
* 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 Externally-Controlled Format String - (134)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 134 (Use of Externally-Controlled Format String)
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
* 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 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.
* 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. Improper Handling of Windows Device Names - (67)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 67 (Improper Handling of Windows Device Names)
The product constructs pathnames from user input, but it does not handle or incorrectly handles a pathname containing a Windows device name such as AUX or CON. This typically leads to denial of service or an information exposure when the application attempts to process the pathname as a regular file.
* 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. Numeric Truncation Error - (197)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 197 (Numeric Truncation Error)
Truncation errors occur when a primitive is cast to a primitive of a smaller size and data is lost in the conversion.
* 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 Handling of Unexpected Data Type - (241)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 241 (Improper Handling of Unexpected Data Type)
The product does not handle or incorrectly handles when a particular element is not the expected type, e.g. it expects a digit (0-9) but is provided with a letter (A-Z).
* 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. Improper Control of a Resource Through its Lifetime - (664)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 664 (Improper Control of a Resource Through its Lifetime)
The product does not maintain or incorrectly maintains control over a resource throughout its lifetime of creation, use, and release.
* 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 Resource Shutdown or Release - (404)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 404 (Improper Resource Shutdown or Release)
The product does not release or incorrectly releases a resource before it is made available for re-use.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Incomplete Cleanup - (459)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 459 (Incomplete Cleanup)
The product does not properly "clean up" and remove temporary or supporting resources after they have been used. Insufficient Cleanup
* 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 Release of Resource after Effective Lifetime - (772)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 772 (Missing Release of Resource after Effective Lifetime)
The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.
* 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. Missing Reference to Active File Descriptor or Handle - (773)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 773 (Missing Reference to Active File Descriptor or Handle)
The product does not properly maintain references to a file descriptor or handle, which prevents that file descriptor/handle from being reclaimed.
* 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. Missing Release of File Descriptor or Handle after Effective Lifetime - (775)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 775 (Missing Release of File Descriptor or Handle after Effective Lifetime)
The product does not release a file descriptor or handle after its effective lifetime has ended, i.e., after the file descriptor/handle is no longer needed.
* 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 Reference to Active Allocated Resource - (771)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 771 (Missing Reference to Active Allocated Resource)
The product does not properly maintain a reference to a resource that has been allocated, which prevents the resource from being reclaimed.
* 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 Expired File Descriptor - (910)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 910 (Use of Expired File Descriptor)
The product uses or accesses a file descriptor after it has been closed. Stale file descriptor
* 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. Operation on Resource in Wrong Phase of Lifetime - (666)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 666 (Operation on Resource in Wrong Phase of Lifetime)
The product performs an operation on a resource at the wrong phase of the resource's lifecycle, which can lead to unexpected behaviors.
* 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. Operation on a Resource after Expiration or Release - (672)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 672 (Operation on a Resource after Expiration or Release)
The product uses, accesses, or otherwise operates on a resource after that resource has been expired, released, or revoked.
* 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. Reliance on Undefined, Unspecified, or Implementation-Defined Behavior - (758)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 758 (Reliance on Undefined, Unspecified, or Implementation-Defined Behavior)
The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.
* 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. Function Call With Incorrect Argument Type - (686)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 686 (Function Call With Incorrect Argument Type)
The product calls a function, procedure, or routine, but the caller specifies an argument that is the wrong data type, which may lead to resultant weaknesses.
* 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. Function Call With Incorrect Number of Arguments - (685)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1163 (SEI CERT C Coding Standard - Guidelines 09. Input Output (FIO)) > 685 (Function Call With Incorrect Number of Arguments)
The product calls a function, procedure, or routine, but the caller specifies too many arguments, or too few arguments, which may lead to undefined behavior and resultant weaknesses.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 10. Environment (ENV) - (1165)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1165 (SEI CERT C Coding Standard - Guidelines 10. Environment (ENV))
Weaknesses in this category are related to the rules and recommendations in the Environment (ENV) section of the SEI CERT C Coding Standard.
* 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 Control Flow Scoping - (705)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1165 (SEI CERT C Coding Standard - Guidelines 10. Environment (ENV)) > 705 (Incorrect Control Flow Scoping)
The product does not properly return control flow to the proper location after it has completed a task or detected an unusual condition.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Use of Potentially Dangerous Function - (676)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1165 (SEI CERT C Coding Standard - Guidelines 10. Environment (ENV)) > 676 (Use of Potentially Dangerous Function)
The product invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1165 (SEI CERT C Coding Standard - Guidelines 10. Environment (ENV)) > 78 (Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'))
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Shell injection Shell metacharacters OS Command Injection
* 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 Argument Delimiters in a Command ('Argument Injection') - (88)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1165 (SEI CERT C Coding Standard - Guidelines 10. Environment (ENV)) > 88 (Improper Neutralization of Argument Delimiters in a Command ('Argument Injection'))
The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 11. Signals (SIG) - (1166)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1166 (SEI CERT C Coding Standard - Guidelines 11. Signals (SIG))
Weaknesses in this category are related to the rules and recommendations in the Signals (SIG) section of the SEI CERT C Coding Standard.
* 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. Signal Handler Use of a Non-reentrant Function - (479)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1166 (SEI CERT C Coding Standard - Guidelines 11. Signals (SIG)) > 479 (Signal Handler Use of a Non-reentrant Function)
The product defines a signal handler that calls a non-reentrant function.
* Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. Improper Synchronization - (662)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1166 (SEI CERT C Coding Standard - Guidelines 11. Signals (SIG)) > 662 (Improper Synchronization)
The product utilizes multiple threads or processes to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR) - (1167)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1167 (SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR))
Weaknesses in this category are related to the rules and recommendations in the Error Handling (ERR) section of the SEI CERT C Coding Standard.
* 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. Missing Initialization of a Variable - (456)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1167 (SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR)) > 456 (Missing Initialization of a Variable)
The product does not initialize critical variables, which causes the execution environment to use unexpected values.
* 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. Unchecked Error Condition - (391)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1167 (SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR)) > 391 (Unchecked Error Condition)
[PLANNED FOR DEPRECATION. SEE MAINTENANCE NOTES AND CONSIDER CWE-252, CWE-248, OR CWE-1069.] Ignoring exceptions and other error conditions may allow an attacker to induce unexpected behavior unnoticed.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Unchecked Return Value - (252)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1167 (SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR)) > 252 (Unchecked Return Value)
The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Incorrect Check of Function Return Value - (253)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1167 (SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR)) > 253 (Incorrect Check of Function Return Value)
The product incorrectly checks a return value from a function, which prevents it from detecting errors or exceptional conditions.
* 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 Potentially Dangerous Function - (676)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1167 (SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR)) > 676 (Use of Potentially Dangerous Function)
The product invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
* 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. Reliance on Undefined, Unspecified, or Implementation-Defined Behavior - (758)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1167 (SEI CERT C Coding Standard - Guidelines 12. Error Handling (ERR)) > 758 (Reliance on Undefined, Unspecified, or Implementation-Defined Behavior)
The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.
* Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 13. Application Programming Interfaces (API) - (1168)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1168 (SEI CERT C Coding Standard - Guidelines 13. Application Programming Interfaces (API))
Weaknesses in this category are related to the rules and recommendations in the Application Programming Interfaces (API) section of the SEI CERT C Coding Standard.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON) - (1169)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1169 (SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON))
Weaknesses in this category are related to the rules and recommendations in the Concurrency (CON) section of the SEI CERT C Coding Standard.
* 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 Locking - (667)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1169 (SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)) > 667 (Improper Locking)
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
* 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. Race Condition within a Thread - (366)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1169 (SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)) > 366 (Race Condition within a Thread)
If two threads of execution use a resource simultaneously, there exists the possibility that resources may be used while invalid, in turn making the state of execution undefined.
* 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 Potentially Dangerous Function - (676)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1169 (SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)) > 676 (Use of Potentially Dangerous Function)
The product invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
* 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. Use of Insufficiently Random Values - (330)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1169 (SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)) > 330 (Use of Insufficiently Random Values)
The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.
* 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. Insecure Temporary File - (377)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1169 (SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)) > 377 (Insecure Temporary File)
Creating and using insecure temporary files can leave application and system data vulnerable to attack.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC) - (1170)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1170 (SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC))
Weaknesses in this category are related to the rules and recommendations in the Miscellaneous (MSC) section of the SEI CERT C Coding Standard.
* 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. Use of a Broken or Risky Cryptographic Algorithm - (327)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1170 (SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC)) > 327 (Use of a Broken or Risky Cryptographic Algorithm)
The product uses a broken or risky cryptographic algorithm or protocol.
* 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. Use of Insufficiently Random Values - (330)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1170 (SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC)) > 330 (Use of Insufficiently Random Values)
The product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection 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 Cryptographically Weak Pseudo-Random Number Generator (PRNG) - (338)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1170 (SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC)) > 338 (Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG))
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG's algorithm is not cryptographically strong.
* 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 Potentially Dangerous Function - (676)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1170 (SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC)) > 676 (Use of Potentially Dangerous Function)
The product invokes a potentially dangerous function that could introduce a vulnerability if it is used incorrectly, but the function can also be used safely.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Insufficient Entropy - (331)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1170 (SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC)) > 331 (Insufficient Entropy)
The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.
* 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. Reliance on Undefined, Unspecified, or Implementation-Defined Behavior - (758)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1170 (SEI CERT C Coding Standard - Guidelines 48. Miscellaneous (MSC)) > 758 (Reliance on Undefined, Unspecified, or Implementation-Defined Behavior)
The product uses an API function, data structure, or other entity in a way that relies on properties that are not always guaranteed to hold for that entity.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 50. POSIX (POS) - (1171)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS))
Weaknesses in this category are related to the rules and recommendations in the POSIX (POS) section of the SEI CERT C Coding Standard.
* 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 Null Termination - (170)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 170 (Improper Null Termination)
The product does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator.
* 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 Inherently Dangerous Function - (242)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 242 (Use of Inherently Dangerous Function)
The product calls a function that can never be guaranteed to work safely.
* 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. Race Condition Enabling Link Following - (363)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 363 (Race Condition Enabling Link Following)
The product checks the status of a file or directory before accessing it, which produces a race condition in which the file can be replaced with a link before the access is performed, causing the product to access the wrong file.
* 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 Behavior Order - (696)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 696 (Incorrect Behavior Order)
The product performs multiple related behaviors, but the behaviors are performed in the wrong order in ways which may produce resultant 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 Check for Dropped Privileges - (273)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 273 (Improper Check for Dropped Privileges)
The product attempts to drop privileges but does not check or incorrectly checks to see if the drop succeeded.
* 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 Locking - (667)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 667 (Improper Locking)
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
* 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. Unchecked Error Condition - (391)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 391 (Unchecked Error Condition)
[PLANNED FOR DEPRECATION. SEE MAINTENANCE NOTES AND CONSIDER CWE-252, CWE-248, OR CWE-1069.] Ignoring exceptions and other error conditions may allow an attacker to induce unexpected behavior unnoticed.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Unchecked Return Value - (252)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 252 (Unchecked Return Value)
The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.
* Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. Incorrect Check of Function Return Value - (253)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1171 (SEI CERT C Coding Standard - Guidelines 50. POSIX (POS)) > 253 (Incorrect Check of Function Return Value)
The product incorrectly checks a return value from a function, which prevents it from detecting errors or exceptional conditions.
+ Category Category - a CWE entry that contains a set of other entries that share a common characteristic. SEI CERT C Coding Standard - Guidelines 51. Microsoft Windows (WIN) - (1172)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1172 (SEI CERT C Coding Standard - Guidelines 51. Microsoft Windows (WIN) )
Weaknesses in this category are related to the rules and recommendations in the Microsoft Windows (WIN) section of the SEI CERT C Coding Standard.
* 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. Mismatched Memory Management Routines - (762)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1172 (SEI CERT C Coding Standard - Guidelines 51. Microsoft Windows (WIN) ) > 762 (Mismatched Memory Management Routines)
The product attempts to return a memory resource to the system, but it calls a release function that is not compatible with the function that was originally used to allocate that resource.
* 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. Free of Memory not on the Heap - (590)
1154 (Weaknesses Addressed by the SEI CERT C Coding Standard) > 1172 (SEI CERT C Coding Standard - Guidelines 51. Microsoft Windows (WIN) ) > 590 (Free of Memory not on the Heap)
The product calls free() on a pointer to memory that was not allocated using associated heap allocation functions such as malloc(), calloc(), or realloc().
+ Vulnerability Mapping Notes

Usage: PROHIBITED

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

Reason: View

Rationale:

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

Comments:

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

Relationship

The relationships in this view were determined based on specific statements within the rules from the standard. Not all rules have direct relationships to individual weaknesses, although they likely have chaining relationships in specific circumstances.
+ References
[REF-598] The Software Engineering Institute. "SEI CERT C Coding Standard". <https://wiki.sei.cmu.edu/confluence/display/c/SEI+CERT+C+Coding+Standard>.
+ View Metrics
CWEs in this view Total CWEs
Weaknesses 78 out of 940
Categories 17 out of 374
Views 0 out of 51
Total 95 out of 1365
+ Content History
+ Submissions
Submission Date Submitter Organization
2018-12-18
(CWE 3.2, 2019-01-03)
CWE Content Team MITRE
+ Modifications
Modification Date Modifier Organization
2020-02-24 CWE Content Team MITRE
updated View_Audience
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes

View Components

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CWE-786: Access of Memory Location Before Start of Buffer

Weakness ID: 786
Vulnerability Mapping: DISCOURAGED This CWE ID should not 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:
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+ Description
The product reads or writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer.
+ Extended Description
This typically occurs when a pointer or its index is decremented to a position before the buffer, when pointer arithmetic results in a position before the beginning of the valid memory location, or when a negative index is used.
+ 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 Memory

For an out-of-bounds read, the attacker may have access to sensitive information. If the sensitive information contains system details, such as the current buffer's position in memory, this knowledge can be used to craft further attacks, possibly with more severe consequences.
Integrity
Availability

Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart

Out of bounds memory access will very likely result in the corruption of relevant memory, and perhaps instructions, possibly leading to a crash.
Integrity

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

If the corrupted memory can be effectively controlled, it may be possible to execute arbitrary code. If the corrupted memory is data rather than instructions, the system will continue to function with improper changes, possibly in violation of an implicit or explicit policy.
+ 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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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. 124 Buffer Underwrite ('Buffer Underflow')
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. 127 Buffer Under-read
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. 1218 Memory Buffer 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 "CISQ Quality Measures (2020)" (CWE-1305)
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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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 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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
+ Demonstrative Examples

Example 1

In the following C/C++ example, a utility function is used to trim trailing whitespace from a character string. The function copies the input string to a local character string and uses a while statement to remove the trailing whitespace by moving backward through the string and overwriting whitespace with a NUL character.

(bad code)
Example Language:
char* trimTrailingWhitespace(char *strMessage, int length) {
char *retMessage;
char *message = malloc(sizeof(char)*(length+1));

// copy input string to a temporary string
char message[length+1];
int index;
for (index = 0; index < length; index++) {
message[index] = strMessage[index];
}
message[index] = '\0';

// trim trailing whitespace
int len = index-1;
while (isspace(message[len])) {
message[len] = '\0';
len--;
}

// return string without trailing whitespace
retMessage = message;
return retMessage;
}

However, this function can cause a buffer underwrite if the input character string contains all whitespace. On some systems the while statement will move backwards past the beginning of a character string and will call the isspace() function on an address outside of the bounds of the local buffer.


Example 2

The following example asks a user for an offset into an array to select an item.

(bad code)
Example Language:

int main (int argc, char **argv) {
char *items[] = {"boat", "car", "truck", "train"};
int index = GetUntrustedOffset();
printf("You selected %s\n", items[index-1]);
}

The programmer allows the user to specify which element in the list to select, however an attacker can provide an out-of-bounds offset, resulting in a buffer over-read (CWE-126).


Example 3

The following is an example of code that may result in a buffer underwrite. This code is attempting to replace the substring "Replace Me" in destBuf with the string stored in srcBuf. It does so by using the function strstr(), which returns a pointer to the found substring in destBuf. Using pointer arithmetic, the starting index of the substring is found.

(bad code)
Example Language:
int main() {
...
char *result = strstr(destBuf, "Replace Me");
int idx = result - destBuf;
strcpy(&destBuf[idx], srcBuf);
...
}

In the case where the substring is not found in destBuf, strstr() will return NULL, causing the pointer arithmetic to be undefined, potentially setting the value of idx to a negative number. If idx is negative, this will result in a buffer underwrite of destBuf.


+ Observed Examples
Reference Description
Unchecked length of SSLv2 challenge value leads to buffer underflow.
Buffer underflow from a small size value with a large buffer (length parameter inconsistency, CWE-130)
Buffer underflow from an all-whitespace string, which causes a counter to be decremented before the buffer while looking for a non-whitespace character.
Buffer underflow resultant from encoded data that triggers an integer overflow.
Product sets an incorrect buffer size limit, leading to "off-by-two" buffer underflow.
Negative value is used in a memcpy() operation, leading to buffer underflow.
Buffer underflow due to mishandled special characters
+ Detection Methods

Fuzzing

Fuzz testing (fuzzing) is a powerful technique for generating large numbers of diverse inputs - either randomly or algorithmically - and dynamically invoking the code with those inputs. Even with random inputs, it is often capable of generating unexpected results such as crashes, memory corruption, or resource consumption. Fuzzing effectively produces repeatable test cases that clearly indicate bugs, which helps developers to diagnose the issues.

Effectiveness: High

+ Memberships
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). 884 CWE Cross-section
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1160 SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1399 Comprehensive Categorization: Memory Safety
+ Vulnerability Mapping Notes

Usage: DISCOURAGED

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

Reasons: Potential Deprecation, Frequent Misuse

Rationale:

The CWE entry might be misused when lower-level CWE entries might be available. It also overlaps existing CWE entries and might be deprecated in the future.

Comments:

If the "Access" operation is known to be a read or a write, then investigate children of entries such as CWE-787: Out-of-bounds Write and CWE-125: Out-of-bounds Read.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
CERT C Secure Coding ARR30-C CWE More Specific Do not form or use out-of-bounds pointers or array subscripts
+ Content History
+ Submissions
Submission Date Submitter Organization
2009-10-21
(CWE 1.6, 2009-10-29)
CWE Content Team MITRE
+ Modifications
Modification Date Modifier Organization
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated Common_Consequences, Demonstrative_Examples, Observed_Examples, Relationships
2017-11-08 CWE Content Team MITRE
updated Common_Consequences, Demonstrative_Examples, Taxonomy_Mappings
2019-01-03 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
2023-01-31 CWE Content Team MITRE
updated Description
2023-04-27 CWE Content Team MITRE
updated Detection_Factors, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
2024-02-29
(CWE 4.14, 2024-02-29)
CWE Content Team MITRE
updated Demonstrative_Examples
2024-07-16
(CWE 4.15, 2024-07-16)
CWE Content Team MITRE
updated Common_Consequences

CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')

Weakness ID: 843
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:
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+ Description
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
+ Extended Description

When the product accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties. In languages without memory safety, such as C and C++, type confusion can lead to out-of-bounds memory access.

While this weakness is frequently associated with unions when parsing data with many different embedded object types in C, it can be present in any application that can interpret the same variable or memory location in multiple ways.

This weakness is not unique to C and C++. For example, errors in PHP applications can be triggered by providing array parameters when scalars are expected, or vice versa. Languages such as Perl, which perform automatic conversion of a variable of one type when it is accessed as if it were another type, can also contain these issues.

+ Alternate Terms
Object Type Confusion
+ 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
Availability
Integrity
Confidentiality

Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart

When a memory buffer is accessed using the wrong type, it could read or write memory out of the bounds of the buffer, if the allocated buffer is smaller than the type that the code is attempting to access, leading to a crash and possibly code execution.
+ 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. 704 Incorrect Type Conversion or Cast
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. 1287 Improper Validation of Specified Type of Input
CanPrecede 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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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. 136 Type 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. 704 Incorrect Type Conversion or Cast
+ 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
+ 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

C (Undetermined Prevalence)

C++ (Undetermined Prevalence)

+ Demonstrative Examples

Example 1

The following code uses a union to support the representation of different types of messages. It formats messages differently, depending on their type.

(bad code)
Example Language:
#define NAME_TYPE 1
#define ID_TYPE 2

struct MessageBuffer
{
int msgType;
union {
char *name;
int nameID;
};
};


int main (int argc, char **argv) {
struct MessageBuffer buf;
char *defaultMessage = "Hello World";

buf.msgType = NAME_TYPE;
buf.name = defaultMessage;
printf("Pointer of buf.name is %p\n", buf.name);
/* This particular value for nameID is used to make the code architecture-independent. If coming from untrusted input, it could be any value. */

buf.nameID = (int)(defaultMessage + 1);
printf("Pointer of buf.name is now %p\n", buf.name);
if (buf.msgType == NAME_TYPE) {
printf("Message: %s\n", buf.name);
}
else {
printf("Message: Use ID %d\n", buf.nameID);
}
}

The code intends to process the message as a NAME_TYPE, and sets the default message to "Hello World." However, since both buf.name and buf.nameID are part of the same union, they can act as aliases for the same memory location, depending on memory layout after compilation.

As a result, modification of buf.nameID - an int - can effectively modify the pointer that is stored in buf.name - a string.

Execution of the program might generate output such as:

Pointer of name is 10830
Pointer of name is now 10831
Message: ello World

Notice how the pointer for buf.name was changed, even though buf.name was not explicitly modified.

In this case, the first "H" character of the message is omitted. However, if an attacker is able to fully control the value of buf.nameID, then buf.name could contain an arbitrary pointer, leading to out-of-bounds reads or writes.


Example 2

The following PHP code accepts a value, adds 5, and prints the sum.

(bad code)
Example Language: PHP 
$value = $_GET['value'];
$sum = $value + 5;
echo "value parameter is '$value'<p>";
echo "SUM is $sum";

When called with the following query string:

value=123

the program calculates the sum and prints out:

SUM is 128

However, the attacker could supply a query string such as:

value[]=123

The "[]" array syntax causes $value to be treated as an array type, which then generates a fatal error when calculating $sum:

Fatal error: Unsupported operand types in program.php on line 2


Example 3

The following Perl code is intended to look up the privileges for user ID's between 0 and 3, by performing an access of the $UserPrivilegeArray reference. It is expected that only userID 3 is an admin (since this is listed in the third element of the array).

(bad code)
Example Language: Perl 
my $UserPrivilegeArray = ["user", "user", "admin", "user"];

my $userID = get_current_user_ID();

if ($UserPrivilegeArray eq "user") {
print "Regular user!\n";
}
else {
print "Admin!\n";
}

print "\$UserPrivilegeArray = $UserPrivilegeArray\n";

In this case, the programmer intended to use "$UserPrivilegeArray->{$userID}" to access the proper position in the array. But because the subscript was omitted, the "user" string was compared to the scalar representation of the $UserPrivilegeArray reference, which might be of the form "ARRAY(0x229e8)" or similar.

Since the logic also "fails open" (CWE-636), the result of this bug is that all users are assigned administrator privileges.

While this is a forced example, it demonstrates how type confusion can have security consequences, even in memory-safe languages.


+ Observed Examples
Reference Description
Type confusion in CSS sequence leads to out-of-bounds read.
Size inconsistency allows code execution, first discovered when it was actively exploited in-the-wild.
Improperly-parsed file containing records of different types leads to code execution when a memory location is interpreted as a different object than intended.
+ 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. 1157 SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1416 Comprehensive Categorization: Resource Lifecycle Management
+ Vulnerability Mapping Notes

Usage: ALLOWED

(this CWE ID 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

Applicable Platform

This weakness is possible in any type-unsafe programming language.

Research Gap

Type confusion weaknesses have received some attention by applied researchers and major software vendors for C and C++ code. Some publicly-reported vulnerabilities probably have type confusion as a root-cause weakness, but these may be described as "memory corruption" instead.

For other languages, there are very few public reports of type confusion weaknesses. These are probably under-studied. Since many programs rely directly or indirectly on loose typing, a potential "type confusion" behavior might be intentional, possibly requiring more manual analysis.

+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
CERT C Secure Coding EXP39-C Exact Do not access a variable through a pointer of an incompatible type
+ References
[REF-811] Mark Dowd, Ryan Smith and David Dewey. "Attacking Interoperability". "Type Confusion Vulnerabilities," page 59. 2009. <http://hustlelabs.com/stuff/bh2009_dowd_smith_dewey.pdf>. URL validated: 2023-04-07.
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 7, "Type Confusion", Page 319. 1st Edition. Addison Wesley. 2006.
+ Content History
+ Submissions
Submission Date Submitter Organization
2011-05-15
(CWE 1.13, 2011-06-01)
CWE Content Team MITRE
+ Modifications
Modification Date Modifier Organization
2012-05-11 CWE Content Team MITRE
updated References
2017-11-08 CWE Content Team MITRE
updated Applicable_Platforms, Taxonomy_Mappings
2019-01-03 CWE Content Team MITRE
updated Relationships
2019-06-20 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated Relationships
2020-06-25 CWE Content Team MITRE
updated Common_Consequences, Relationships
2022-04-28 CWE Content Team MITRE
updated Research_Gaps
2023-01-31 CWE Content Team MITRE
updated Description
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 Demonstrative_Examples

CWE-481: Assigning instead of Comparing

Weakness ID: 481
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: 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.
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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Edit Custom Filter


+ Description
The code uses an operator for assignment when the intention was to perform a comparison.
+ Extended Description
In many languages the compare statement is very close in appearance to the assignment statement and are often confused. This bug is generally the result of a typo and usually causes obvious problems with program execution. If the comparison is in an if statement, the if statement will usually evaluate the value of the right-hand side of the predicate.
+ 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
Other

Technical Impact: Alter Execution Logic

+ Potential Mitigations

Phase: Testing

Many IDEs and static analysis products will detect this problem.

Phase: Implementation

Place constants on the left. If one attempts to assign a constant with a variable, the compiler will produce an error.
+ 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 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. 480 Use of Incorrect Operator
CanPrecede 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. 697 Incorrect Comparison
+ 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
+ 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

C (Undetermined Prevalence)

C++ (Undetermined Prevalence)

Java (Undetermined Prevalence)

C# (Undetermined Prevalence)

+ Likelihood Of Exploit
Low
+ Demonstrative Examples

Example 1

The following C/C++ and C# examples attempt to validate an int input parameter against the integer value 100.

(bad code)
Example Language:
int isValid(int value) {
if (value=100) {
printf("Value is valid\n");
return(1);
}
printf("Value is not valid\n");
return(0);
}
(bad code)
Example Language: C# 
bool isValid(int value) {
if (value=100) {
Console.WriteLine("Value is valid.");
return true;
}
Console.WriteLine("Value is not valid.");
return false;
}

However, the expression to be evaluated in the if statement uses the assignment operator "=" rather than the comparison operator "==". The result of using the assignment operator instead of the comparison operator causes the int variable to be reassigned locally and the expression in the if statement will always evaluate to the value on the right hand side of the expression. This will result in the input value not being properly validated, which can cause unexpected results.


Example 2

In this example, we show how assigning instead of comparing can impact code when values are being passed by reference instead of by value. Consider a scenario in which a string is being processed from user input. Assume the string has already been formatted such that different user inputs are concatenated with the colon character. When the processString function is called, the test for the colon character will result in an insertion of the colon character instead, adding new input separators. Since the string was passed by reference, the data sentinels will be inserted in the original string (CWE-464), and further processing of the inputs will be altered, possibly malformed..

(bad code)
Example Language:
void processString (char *str) {
int i;

for(i=0; i<strlen(str); i++) {
if (isalnum(str[i])){
processChar(str[i]);
}
else if (str[i] = ':') {
movingToNewInput();}
}
}
}

Example 3

The following Java example attempts to perform some processing based on the boolean value of the input parameter. However, the expression to be evaluated in the if statement uses the assignment operator "=" rather than the comparison operator "==". As with the previous examples, the variable will be reassigned locally and the expression in the if statement will evaluate to true and unintended processing may occur.

(bad code)
Example Language: Java 
public void checkValid(boolean isValid) {
if (isValid = true) {
System.out.println("Performing processing");
doSomethingImportant();
}
else {
System.out.println("Not Valid, do not perform processing");
return;
}
}

While most Java compilers will catch the use of an assignment operator when a comparison operator is required, for boolean variables in Java the use of the assignment operator within an expression is allowed. If possible, try to avoid using comparison operators on boolean variables in java. Instead, let the values of the variables stand for themselves, as in the following code.

(good code)
Example Language: Java 
public void checkValid(boolean isValid) {
if (isValid) {
System.out.println("Performing processing");
doSomethingImportant();
}
else {
System.out.println("Not Valid, do not perform processing");
return;
}
}

Alternatively, to test for false, just use the boolean NOT operator.

(good code)
Example Language: Java 
public void checkValid(boolean isValid) {
if (!isValid) {
System.out.println("Not Valid, do not perform processing");
return;
}
System.out.println("Performing processing");
doSomethingImportant();
}

Example 4

The following example demonstrates the weakness.

(bad code)
Example Language:
void called(int foo){
if (foo=1) printf("foo\n");
}
int main() {

called(2);
return 0;
}

+ 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. 998 SFP Secondary Cluster: Glitch in Computation
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1157 SEI CERT C Coding Standard - Guidelines 03. Expressions (EXP)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1410 Comprehensive Categorization: Insufficient Control Flow Management
+ Vulnerability Mapping Notes

Usage: ALLOWED

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

Reason: Acceptable-Use

Rationale:

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

Comments:

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
CLASP Assigning instead of comparing
Software Fault Patterns SFP1 Glitch in computation
CERT C Secure Coding EXP45-C CWE More Abstract Do not perform assignments in selection statements
+ 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-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 6, "Typos", Page 289. 1st Edition. Addison Wesley. 2006.
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-07-19
(CWE Draft 3, 2006-07-19)
CLASP
+ 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, Description, Relationships, Other_Notes, Taxonomy_Mappings
2009-05-27 CWE Content Team MITRE
updated Demonstrative_Examples
2009-07-27 CWE Content Team MITRE
updated Description, Other_Notes
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2012-05-11 CWE Content Team MITRE
updated References, Relationships
2012-10-30 CWE Content Team MITRE
updated Demonstrative_Examples, Potential_Mitigations
2014-07-30 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2017-01-19 CWE Content Team MITRE
updated Relationships
2017-11-08 CWE Content Team MITRE
updated Demonstrative_Examples, Taxonomy_Mappings
2019-01-03 CWE Content Team MITRE
updated Relationships
2020-02-24 CWE Content Team MITRE
updated References, Relationships
2021-03-15 CWE Content Team MITRE
updated Demonstrative_Examples, Potential_Mitigations
2023-04-27 CWE Content Team MITRE
updated Detection_Factors, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes

CWE-587: Assignment of a Fixed Address to a Pointer

Weakness ID: 587
Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: 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.
View customized information:
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+ Description
The product sets a pointer to a specific address other than NULL or 0.
+ Extended Description
Using a fixed address is not portable, because that address will probably not be valid in all environments or platforms.
+ Common Consequences
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

Technical Impact: Execute Unauthorized Code or Commands

If one executes code at a known location, an attacker might be able to inject code there beforehand.
Availability

Technical Impact: DoS: Crash, Exit, or Restart; Reduce Maintainability; Reduce Reliability

If the code is ported to another platform or environment, the pointer is likely to be invalid and cause a crash.
Confidentiality
Integrity

Technical Impact: Read Memory; Modify Memory

The data at a known pointer location can be easily read or influenced by an attacker.
+ Potential Mitigations

Phase: Implementation

Never set a pointer to a fixed address.
+ 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 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. 344 Use of Invariant Value in Dynamically Changing Context
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. 758 Reliance on Undefined, Unspecified, or Implementation-Defined Behavior
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. 465 Pointer Issues
+ 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
+ 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

C (Undetermined Prevalence)

C++ (Undetermined Prevalence)

C# (Undetermined Prevalence)

Class: Assembly (Undetermined Prevalence)

+ Demonstrative Examples

Example 1

This code assumes a particular function will always be found at a particular address. It assigns a pointer to that address and calls the function.

(bad code)
Example Language:
int (*pt2Function) (float, char, char)=0x08040000;
int result2 = (*pt2Function) (12, 'a', 'b');
// Here we can inject code to execute.

The same function may not always be found at the same memory address. This could lead to a crash, or an attacker may alter the memory at the expected address, leading to arbitrary code execution.


+ Weakness Ordinalities
Ordinality Description
Indirect
(where the weakness is a quality issue that might indirectly make it easier to introduce security-relevant weaknesses or make them more difficult to detect)
+ Memberships
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. 738 CERT C Secure Coding Standard (2008) Chapter 5 - Integers (INT)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 872 CERT C++ Secure Coding Section 04 - Integers (INT)
MemberOf 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. 998 SFP Secondary Cluster: Glitch in Computation
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1158 SEI CERT C Coding Standard - Guidelines 04. Integers (INT)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1399 Comprehensive Categorization: Memory Safety
+ Vulnerability Mapping Notes

Usage: ALLOWED

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

Reason: Acceptable-Use

Rationale:

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

Comments:

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
CERT C Secure Coding INT36-C Imprecise Converting a pointer to integer or integer to pointer
Software Fault Patterns SFP1 Glitch in computation
+ Content History
+ Submissions
Submission Date Submitter Organization
2006-12-15
(CWE Draft 5, 2006-12-15)
CWE Content Team MITRE
+ Modifications
Modification Date Modifier Organization
2008-07-01 Eric Dalci Cigital
updated Time_of_Introduction
2008-08-01 KDM Analytics
added/updated white box definitions
2008-09-08 CWE Content Team MITRE
updated Applicable_Platforms, Description, Relationships, Other_Notes, Weakness_Ordinalities
2008-11-24 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2009-03-10 CWE Content Team MITRE
updated Relationships
2009-07-27 CWE Content Team MITRE
updated Common_Consequences, Description, Other_Notes
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2011-09-13 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2012-05-11 CWE Content Team MITRE
updated Demonstrative_Examples, Relationships
2014-07-30 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2017-11-08 CWE Content Team MITRE
updated Applicable_Platforms, Taxonomy_Mappings, White_Box_Definitions
2019-01-03 CWE Content Team MITRE
updated Relationships
2021-03-15 CWE Content Team MITRE
updated Common_Consequences, Weakness_Ordinalities
2023-01-31 CWE Content Team MITRE
updated Description
2023-04-27 CWE Content Team MITRE
updated Relationships, Time_of_Introduction, Type
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
2024-02-29
(CWE 4.14, 2024-02-29)
CWE Content Team MITRE
updated Demonstrative_Examples

CWE-805: Buffer Access with Incorrect Length Value

Weakness ID: 805
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 uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.
+ Extended Description
When the length value exceeds the size of the destination, a buffer overflow could occur.
+ Common Consequences
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

Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands

Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy. This can often be used to subvert any other security service.
Availability

Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)

Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
+ Potential Mitigations

Phase: Requirements

Strategy: Language Selection

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

For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.

Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

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.

Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.

Note: This is not a complete solution, since many buffer overflows are not related to strings.

Phases: Operation; Build and Compilation

Strategy: Environment Hardening

Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.

D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.

Effectiveness: Defense in Depth

Note:

This is not necessarily a complete solution, since these mechanisms only detect certain types of overflows. In addition, the result is still a denial of service, since the typical response is to exit the application.

Phase: Implementation

Consider adhering to the following rules when allocating and managing an application's memory:

  • Double check that the buffer is as large as specified.
  • When using functions that accept a number of bytes to copy, such as strncpy(), be aware that if the destination buffer size is equal to the source buffer size, it may not NULL-terminate the string.
  • Check buffer boundaries if accessing the buffer in a loop and make sure there is no danger of writing past the allocated space.
  • If necessary, truncate all input strings to a reasonable length before passing them to the copy and concatenation functions.

Phase: Architecture and Design

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

Phases: Operation; Build and Compilation

Strategy: Environment Hardening

Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.

Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing" (for Windows) and "prelinking" (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.

For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

Effectiveness: Defense in Depth

Note: These techniques do not provide a complete solution. For instance, exploits frequently use a bug that discloses memory addresses in order to maximize reliability of code execution [REF-1337]. It has also been shown that a side-channel attack can bypass ASLR [REF-1333].

Phase: Operation

Strategy: Environment Hardening

Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.

For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].

Effectiveness: Defense in Depth

Note: This is not a complete solution, since buffer overflows could be used to overwrite nearby variables to modify the software's state in dangerous ways. In addition, it cannot be used in cases in which self-modifying code is required. Finally, an attack could still cause a denial of service, since the typical response is to exit the application.

Phases: Architecture and Design; Operation

Strategy: Environment Hardening

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

Phases: Architecture and Design; Operation

Strategy: Sandbox or Jail

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

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

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

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

Effectiveness: Limited

Note: The effectiveness of this mitigation depends on the prevention capabilities of the specific sandbox or jail being used and might only help to reduce the scope of an attack, such as restricting the attacker to certain system calls or limiting the portion of the file system that can be accessed.
+ Relationships
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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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. 806 Buffer Access Using Size of Source Buffer
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. 130 Improper Handling of Length Parameter Inconsistency
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. 1218 Memory Buffer 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 "CISQ Quality Measures (2020)" (CWE-1305)
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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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 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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
+ 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
+ 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

C (Often Prevalent)

C++ (Often Prevalent)

Class: Assembly (Undetermined Prevalence)

+ Likelihood Of Exploit
High
+ Demonstrative Examples

Example 1

This example takes an IP address from a user, verifies that it is well formed and then looks up the hostname and copies it into a buffer.

(bad code)
Example Language:
void host_lookup(char *user_supplied_addr){
struct hostent *hp;
in_addr_t *addr;
char hostname[64];
in_addr_t inet_addr(const char *cp);

/*routine that ensures user_supplied_addr is in the right format for conversion */

validate_addr_form(user_supplied_addr);
addr = inet_addr(user_supplied_addr);
hp = gethostbyaddr( addr, sizeof(struct in_addr), AF_INET);
strcpy(hostname, hp->h_name);
}

This function allocates a buffer of 64 bytes to store the hostname under the assumption that the maximum length value of hostname is 64 bytes, however there is no guarantee that the hostname will not be larger than 64 bytes. If an attacker specifies an address which resolves to a very large hostname, then the function may overwrite sensitive data or even relinquish control flow to the attacker.

Note that this example also contains an unchecked return value (CWE-252) that can lead to a NULL pointer dereference (CWE-476).


Example 2

In the following example, it is possible to request that memcpy move a much larger segment of memory than assumed:

(bad code)
Example Language:
int returnChunkSize(void *) {

/* if chunk info is valid, return the size of usable memory,

* else, return -1 to indicate an error

*/
...
}
int main() {
...
memcpy(destBuf, srcBuf, (returnChunkSize(destBuf)-1));
...
}

If returnChunkSize() happens to encounter an error it will return -1. Notice that the return value is not checked before the memcpy operation (CWE-252), so -1 can be passed as the size argument to memcpy() (CWE-805). Because memcpy() assumes that the value is unsigned, it will be interpreted as MAXINT-1 (CWE-195), and therefore will copy far more memory than is likely available to the destination buffer (CWE-787, CWE-788).


Example 3

In the following example, the source character string is copied to the dest character string using the method strncpy.

(bad code)
Example Language:
...
char source[21] = "the character string";
char dest[12];
strncpy(dest, source, sizeof(source)-1);
...

However, in the call to strncpy the source character string is used within the sizeof call to determine the number of characters to copy. This will create a buffer overflow as the size of the source character string is greater than the dest character string. The dest character string should be used within the sizeof call to ensure that the correct number of characters are copied, as shown below.

(good code)
Example Language:
...
char source[21] = "the character string";
char dest[12];
strncpy(dest, source, sizeof(dest)-1);
...

Example 4

In this example, the method outputFilenameToLog outputs a filename to a log file. The method arguments include a pointer to a character string containing the file name and an integer for the number of characters in the string. The filename is copied to a buffer where the buffer size is set to a maximum size for inputs to the log file. The method then calls another method to save the contents of the buffer to the log file.

(bad code)
Example Language:
#define LOG_INPUT_SIZE 40

// saves the file name to a log file
int outputFilenameToLog(char *filename, int length) {
int success;

// buffer with size set to maximum size for input to log file
char buf[LOG_INPUT_SIZE];

// copy filename to buffer
strncpy(buf, filename, length);

// save to log file
success = saveToLogFile(buf);

return success;
}

However, in this case the string copy method, strncpy, mistakenly uses the length method argument to determine the number of characters to copy rather than using the size of the local character string, buf. This can lead to a buffer overflow if the number of characters contained in character string pointed to by filename is larger then the number of characters allowed for the local character string. The string copy method should use the buf character string within a sizeof call to ensure that only characters up to the size of the buf array are copied to avoid a buffer overflow, as shown below.

(good code)
Example Language:
...
// copy filename to buffer
strncpy(buf, filename, sizeof(buf)-1);
...

Example 5

Windows provides the MultiByteToWideChar(), WideCharToMultiByte(), UnicodeToBytes(), and BytesToUnicode() functions to convert between arbitrary multibyte (usually ANSI) character strings and Unicode (wide character) strings. The size arguments to these functions are specified in different units, (one in bytes, the other in characters) making their use prone to error.

In a multibyte character string, each character occupies a varying number of bytes, and therefore the size of such strings is most easily specified as a total number of bytes. In Unicode, however, characters are always a fixed size, and string lengths are typically given by the number of characters they contain. Mistakenly specifying the wrong units in a size argument can lead to a buffer overflow.

The following function takes a username specified as a multibyte string and a pointer to a structure for user information and populates the structure with information about the specified user. Since Windows authentication uses Unicode for usernames, the username argument is first converted from a multibyte string to a Unicode string.

(bad code)
Example Language:
void getUserInfo(char *username, struct _USER_INFO_2 info){
WCHAR unicodeUser[UNLEN+1];
MultiByteToWideChar(CP_ACP, 0, username, -1, unicodeUser, sizeof(unicodeUser));
NetUserGetInfo(NULL, unicodeUser, 2, (LPBYTE *)&info);
}

This function incorrectly passes the size of unicodeUser in bytes instead of characters. The call to MultiByteToWideChar() can therefore write up to (UNLEN+1)*sizeof(WCHAR) wide characters, or (UNLEN+1)*sizeof(WCHAR)*sizeof(WCHAR) bytes, to the unicodeUser array, which has only (UNLEN+1)*sizeof(WCHAR) bytes allocated.

If the username string contains more than UNLEN characters, the call to MultiByteToWideChar() will overflow the buffer unicodeUser.


+ Observed Examples
Reference Description
Chain: large length value causes buffer over-read (CWE-126)
Use of packet length field to make a calculation, then copy into a fixed-size buffer
Chain: retrieval of length value from an uninitialized memory location
Crafted length value in document reader leads to buffer overflow
SSL server overflow when the sum of multiple length fields exceeds a given value
Language interpreter API function doesn't validate length argument, leading to information exposure
+ Weakness Ordinalities
Ordinality Description
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Primary
(where the weakness exists independent of other weaknesses)
+ Detection Methods

Automated Static Analysis

This weakness can often be detected using automated static analysis tools. Many modern tools use data flow analysis or constraint-based techniques to minimize the number of false positives.

Automated static analysis generally does not account for environmental considerations when reporting out-of-bounds memory operations. This can make it difficult for users to determine which warnings should be investigated first. For example, an analysis tool might report buffer overflows that originate from command line arguments in a program that is not expected to run with setuid or other special privileges.

Effectiveness: High

Note: Detection techniques for buffer-related errors are more mature than for most other weakness types.

Automated Dynamic Analysis

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

Effectiveness: Moderate

Note: Without visibility into the code, black box methods may not be able to sufficiently distinguish this weakness from others, requiring manual methods to diagnose the underlying problem.

Manual Analysis

Manual analysis can be useful for finding this weakness, but it might not achieve desired code coverage within limited time constraints. This becomes difficult for weaknesses that must be considered for all inputs, since the attack surface can be too large.
+ Affected Resources
  • Memory
+ Memberships
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. 740 CERT C Secure Coding Standard (2008) Chapter 7 - Arrays (ARR)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 802 2010 Top 25 - Risky Resource Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 867 2011 Top 25 - Weaknesses On the Cusp
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 874 CERT C++ Secure Coding Section 06 - Arrays and the STL (ARR)
MemberOf 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. 1160 SEI CERT C Coding Standard - Guidelines 06. Arrays (ARR)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1399 Comprehensive Categorization: Memory Safety
+ Vulnerability Mapping Notes

Usage: ALLOWED

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

Reason: Acceptable-Use

Rationale:

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

Comments:

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
CERT C Secure Coding ARR38-C Imprecise Guarantee that library functions do not form invalid pointers
+ References
[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 6, "Why ACLs Are Important" Page 171. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.
[REF-58] Michael Howard. "Address Space Layout Randomization in Windows Vista". <https://learn.microsoft.com/en-us/archive/blogs/michael_howard/address-space-layout-randomization-in-windows-vista>. URL validated: 2023-04-07.
[REF-59] Arjan van de Ven. "Limiting buffer overflows with ExecShield". <https://archive.is/saAFo>. URL validated: 2023-04-07.
[REF-60] "PaX". <https://en.wikipedia.org/wiki/Executable_space_protection#PaX>. URL validated: 2023-04-07.
[REF-741] Jason Lam. "Top 25 Series - Rank 12 - Buffer Access with Incorrect Length Value". SANS Software Security Institute. 2010-03-11. <https://web.archive.org/web/20100316043717/http://blogs.sans.org:80/appsecstreetfighter/2010/03/11/top-25-series-rank-12-buffer-access-with-incorrect-length-value/>. URL validated: 2023-04-07.
[REF-57] Matt Messier and John Viega. "Safe C String Library v1.0.3". <http://www.gnu-darwin.org/www001/ports-1.5a-CURRENT/devel/safestr/work/safestr-1.0.3/doc/safestr.html>. URL validated: 2023-04-07.
[REF-56] Microsoft. "Using the Strsafe.h Functions". <https://learn.microsoft.com/en-us/windows/win32/menurc/strsafe-ovw?redirectedfrom=MSDN>. URL validated: 2023-04-07.
[REF-61] Microsoft. "Understanding DEP as a mitigation technology part 1". <https://msrc.microsoft.com/blog/2009/06/understanding-dep-as-a-mitigation-technology-part-1/>. URL validated: 2023-04-07.
[REF-76] Sean Barnum and Michael Gegick. "Least Privilege". 2005-09-14. <https://web.archive.org/web/20211209014121/https://www.cisa.gov/uscert/bsi/articles/knowledge/principles/least-privilege>. URL validated: 2023-04-07.
[REF-64] Grant Murphy. "Position Independent Executables (PIE)". Red Hat. 2012-11-28. <https://www.redhat.com/en/blog/position-independent-executables-pie>. URL validated: 2023-04-07.
[REF-1332] John Richard Moser. "Prelink and address space randomization". 2006-07-05. <https://lwn.net/Articles/190139/>. URL validated: 2023-04-26.
[REF-1333] Dmitry Evtyushkin, Dmitry Ponomarev, Nael Abu-Ghazaleh. "Jump Over ASLR: Attacking Branch Predictors to Bypass ASLR". 2016. <http://www.cs.ucr.edu/~nael/pubs/micro16.pdf>. URL validated: 2023-04-26.
[REF-1334] D3FEND. "Stack Frame Canary Validation (D3-SFCV)". 2023. <https://d3fend.mitre.org/technique/d3f:StackFrameCanaryValidation/>. URL validated: 2023-04-26.
[REF-1335] D3FEND. "Segment Address Offset Randomization (D3-SAOR)". 2023. <https://d3fend.mitre.org/technique/d3f:SegmentAddressOffsetRandomization/>. URL validated: 2023-04-26.
[REF-1336] D3FEND. "Process Segment Execution Prevention (D3-PSEP)". 2023. <https://d3fend.mitre.org/technique/d3f:ProcessSegmentExecutionPrevention/>. URL validated: 2023-04-26.
[REF-1337] Alexander Sotirov and Mark Dowd. "Bypassing Browser Memory Protections: Setting back browser security by 10 years". Memory information leaks. 2008. <https://www.blackhat.com/presentations/bh-usa-08/Sotirov_Dowd/bh08-sotirov-dowd.pdf>. URL validated: 2023-04-26.
+ Content History
+ Submissions
Submission Date Submitter Organization
2010-01-15
(CWE 1.8, 2010-02-16)
CWE Content Team MITRE
+ Modifications
Modification Date Modifier Organization
2010-04-05 CWE Content Team MITRE
updated Related_Attack_Patterns
2010-06-21 CWE Content Team MITRE
updated Common_Consequences, Potential_Mitigations, References
2010-09-27 CWE Content Team MITRE
updated Potential_Mitigations
2010-12-13 CWE Content Team MITRE
updated Potential_Mitigations
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2011-06-27 CWE Content Team MITRE
updated Demonstrative_Examples, Observed_Examples, Relationships
2011-09-13 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2012-05-11 CWE Content Team MITRE
updated Potential_Mitigations, References, Relationships
2012-10-30 CWE Content Team MITRE
updated Potential_Mitigations
2014-02-18 CWE Content Team MITRE
updated Potential_Mitigations, References
2014-06-23 CWE Content Team MITRE
updated Demonstrative_Examples
2017-11-08 CWE Content Team MITRE
updated Applicable_Platforms, Causal_Nature, Demonstrative_Examples, Likelihood_of_Exploit, References, Taxonomy_Mappings
2018-03-27 CWE Content Team MITRE
updated References
2019-01-03 CWE Content Team MITRE
updated Relationships
2019-06-20 CWE Content Team MITRE
updated Related_Attack_Patterns
2020-02-24 CWE Content Team MITRE
updated Relationships
2020-06-25 CWE Content Team MITRE
updated Common_Consequences
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 Demonstrative_Examples, Potential_Mitigations
2022-10-13 CWE Content Team MITRE
updated References
2023-01-31 CWE Content Team MITRE
updated Description, Detection_Factors, Potential_Mitigations
2023-04-27 CWE Content Team MITRE
updated Potential_Mitigations, References, Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
2024-02-29
(CWE 4.14, 2024-02-29)
CWE Content Team MITRE
updated Demonstrative_Examples

CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

Weakness ID: 120
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.
View customized information:
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+ Description
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.
+ Extended Description
A buffer overflow condition exists when a product attempts to put more data in a buffer than it can hold, or when it attempts to put data in a memory area outside of the boundaries of a buffer. The simplest type of error, and the most common cause of buffer overflows, is the "classic" case in which the product copies the buffer without restricting how much is copied. Other variants exist, but the existence of a classic overflow strongly suggests that the programmer is not considering even the most basic of security protections.
+ Alternate Terms
Classic Buffer Overflow:
This term was frequently used by vulnerability researchers during approximately 1995 to 2005 to differentiate buffer copies without length checks (which had been known about for decades) from other emerging weaknesses that still involved invalid accesses of buffers, as vulnerability researchers began to develop advanced exploitation techniques.
Unbounded Transfer
+ Common Consequences
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

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of the product's implicit security policy. This can often be used to subvert any other security service.
Availability

Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)

Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the product into an infinite loop.
+ Potential Mitigations

Phase: Requirements

Strategy: Language Selection

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

For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.

Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

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.

Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.

Note: This is not a complete solution, since many buffer overflows are not related to strings.

Phases: Operation; Build and Compilation

Strategy: Environment Hardening

Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.

D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.

Effectiveness: Defense in Depth

Note:

This is not necessarily a complete solution, since these mechanisms only detect certain types of overflows. In addition, the result is still a denial of service, since the typical response is to exit the application.

Phase: Implementation

Consider adhering to the following rules when allocating and managing an application's memory:

  • Double check that your buffer is as large as you specify.
  • When using functions that accept a number of bytes to copy, such as strncpy(), be aware that if the destination buffer size is equal to the source buffer size, it may not NULL-terminate the string.
  • Check buffer boundaries if accessing the buffer in a loop and make sure there is no danger of writing past the allocated space.
  • If necessary, truncate all input strings to a reasonable length before passing them to the copy and concatenation functions.

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.

Phase: Architecture and Design

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

Phases: Operation; Build and Compilation

Strategy: Environment Hardening

Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.

Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing" (for Windows) and "prelinking" (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.

For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

Effectiveness: Defense in Depth

Note: These techniques do not provide a complete solution. For instance, exploits frequently use a bug that discloses memory addresses in order to maximize reliability of code execution [REF-1337]. It has also been shown that a side-channel attack can bypass ASLR [REF-1333]

Phase: Operation

Strategy: Environment Hardening

Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.

For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].

Effectiveness: Defense in Depth

Note: This is not a complete solution, since buffer overflows could be used to overwrite nearby variables to modify the software's state in dangerous ways. In addition, it cannot be used in cases in which self-modifying code is required. Finally, an attack could still cause a denial of service, since the typical response is to exit the application.

Phases: Build and Compilation; Operation

Most mitigating technologies at the compiler or OS level to date address only a subset of buffer overflow problems and rarely provide complete protection against even that subset. It is good practice to implement strategies to increase the workload of an attacker, such as leaving the attacker to guess an unknown value that changes every program execution.

Phase: Implementation

Replace unbounded copy functions with analogous functions that support length arguments, such as strcpy with strncpy. Create these if they are not available.

Effectiveness: Moderate

Note: This approach is still susceptible to calculation errors, including issues such as off-by-one errors (CWE-193) and incorrectly calculating buffer lengths (CWE-131).

Phase: Architecture and Design

Strategy: Enforcement by Conversion

When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.

Phases: Architecture and Design; Operation

Strategy: Environment Hardening

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

Phases: Architecture and Design; Operation

Strategy: Sandbox or Jail

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

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

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

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

Effectiveness: Limited

Note: The effectiveness of this mitigation depends on the prevention capabilities of the specific sandbox or jail being used and might only help to reduce the scope of an attack, such as restricting the attacker to certain system calls or limiting the portion of the file system that can be accessed.
+ Relationships
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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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. 785 Use of Path Manipulation Function without Maximum-sized Buffer
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. 170 Improper Null Termination
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. 231 Improper Handling of Extra Values
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. 416 Use After Free
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. 456 Missing Initialization of a Variable
CanPrecede 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. 123 Write-what-where Condition
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. 1218 Memory Buffer 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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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 Quality Measures (2020)" (CWE-1305)
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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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 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. 119 Improper Restriction of Operations within the Bounds of a Memory Buffer
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 "Seven Pernicious Kingdoms" (CWE-700)
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. 20 Improper Input Validation
+ 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
+ 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

C (Undetermined Prevalence)

C++ (Undetermined Prevalence)

Class: Assembly (Undetermined Prevalence)

+ Likelihood Of Exploit
High
+ Demonstrative Examples

Example 1

The following code asks the user to enter their last name and then attempts to store the value entered in the last_name array.

(bad code)
Example Language:
char last_name[20];
printf ("Enter your last name: ");
scanf ("%s", last_name);

The problem with the code above is that it does not restrict or limit the size of the name entered by the user. If the user enters "Very_very_long_last_name" which is 24 characters long, then a buffer overflow will occur since the array can only hold 20 characters total.


Example 2

The following code attempts to create a local copy of a buffer to perform some manipulations to the data.

(bad code)
Example Language:
void manipulate_string(char * string){
char buf[24];
strcpy(buf, string);
...
}

However, the programmer does not ensure that the size of the data pointed to by string will fit in the local buffer and copies the data with the potentially dangerous strcpy() function. This may result in a buffer overflow condition if an attacker can influence the contents of the string parameter.


Example 3

The code below calls the gets() function to read in data from the command line.

(bad code)
Example Language:
char buf[24];
printf("Please enter your name and press <Enter>\n");
gets(buf);
...
}

However, gets() is inherently unsafe, because it copies all input from STDIN to the buffer without checking size. This allows the user to provide a string that is larger than the buffer size, resulting in an overflow condition.


Example 4

In the following example, a server accepts connections from a client and processes the client request. After accepting a client connection, the program will obtain client information using the gethostbyaddr method, copy the hostname of the client that connected to a local variable and output the hostname of the client to a log file.

(bad code)
Example Language:
...
struct hostent *clienthp;
char hostname[MAX_LEN];

// create server socket, bind to server address and listen on socket
...

// accept client connections and process requests
int count = 0;
for (count = 0; count < MAX_CONNECTIONS; count++) {

int clientlen = sizeof(struct sockaddr_in);
int clientsocket = accept(serversocket, (struct sockaddr *)&clientaddr, &clientlen);

if (clientsocket >= 0) {
clienthp = gethostbyaddr((char*) &clientaddr.sin_addr.s_addr, sizeof(clientaddr.sin_addr.s_addr), AF_INET);
strcpy(hostname, clienthp->h_name);
logOutput("Accepted client connection from host ", hostname);

// process client request
...
close(clientsocket);
}
}
close(serversocket);

...

However, the hostname of the client that connected may be longer than the allocated size for the local hostname variable. This will result in a buffer overflow when copying the client hostname to the local variable using the strcpy method.


+ Observed Examples
Reference Description
buffer overflow using command with long argument
buffer overflow in local program using long environment variable
buffer overflow in comment characters, when product increments a counter for a ">" but does not decrement for "<"
By replacing a valid cookie value with an extremely long string of characters, an attacker may overflow the application's buffers.
By replacing a valid cookie value with an extremely long string of characters, an attacker may overflow the application's buffers.
+ Weakness Ordinalities
Ordinality Description
Resultant
(where the weakness is typically related to the presence of some other weaknesses)
Primary
(where the weakness exists independent of other weaknesses)
+ Detection Methods

Automated Static Analysis

This weakness can often be detected using automated static analysis tools. Many modern tools use data flow analysis or constraint-based techniques to minimize the number of false positives.

Automated static analysis generally does not account for environmental considerations when reporting out-of-bounds memory operations. This can make it difficult for users to determine which warnings should be investigated first. For example, an analysis tool might report buffer overflows that originate from command line arguments in a program that is not expected to run with setuid or other special privileges.

Effectiveness: High

Note: Detection techniques for buffer-related errors are more mature than for most other weakness types.

Automated Dynamic Analysis

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

Manual Analysis

Manual analysis can be useful for finding this weakness, but it might not achieve desired code coverage within limited time constraints. This becomes difficult for weaknesses that must be considered for all inputs, since the attack surface can be too large.

Automated Static Analysis - Binary or Bytecode

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

Highly cost effective:
  • Bytecode Weakness Analysis - including disassembler + source code weakness analysis
  • Binary Weakness Analysis - including disassembler + source code weakness analysis

Effectiveness: High

Manual Static Analysis - Binary or Bytecode

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

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

Effectiveness: SOAR Partial

Dynamic Analysis with Automated Results Interpretation

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

Cost effective for partial coverage:
  • 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:
  • 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:

Highly cost effective:
  • Source code Weakness Analyzer
  • Context-configured Source Code Weakness Analyzer

Effectiveness: High

Architecture or Design Review

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

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

Effectiveness: High

+ Functional Areas
  • Memory Management
+ Affected Resources
  • Memory
+ 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. 722 OWASP Top Ten 2004 Category A1 - Unvalidated Input
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 726 OWASP Top Ten 2004 Category A5 - Buffer Overflows
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 741 CERT C Secure Coding Standard (2008) Chapter 8 - Characters and Strings (STR)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 802 2010 Top 25 - Risky Resource Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 865 2011 Top 25 - Risky Resource Management
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 875 CERT C++ Secure Coding Section 07 - Characters and Strings (STR)
MemberOf 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. 970 SFP Secondary Cluster: Faulty Buffer Access
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1129 CISQ Quality Measures (2016) - Reliability
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1131 CISQ Quality Measures (2016) - Security
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1161 SEI CERT C Coding Standard - Guidelines 07. Characters and Strings (STR)
MemberOf CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. 1399 Comprehensive Categorization: Memory Safety
+ Vulnerability Mapping Notes

Usage: ALLOWED-WITH-REVIEW

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

Reason: Frequent Misuse

Rationale:

There are some indications that this CWE ID might be misused and selected simply because it mentions "buffer overflow" - an increasingly vague term. This CWE entry is only appropriate for "Buffer Copy" operations (not buffer reads), in which where there is no "Checking [the] Size of Input", and (by implication of the copy) writing past the end of the buffer.

Comments:

If the vulnerability being analyzed involves out-of-bounds reads, then consider CWE-125 or descendants. For root cause analysis: if there is any input validation, consider children of CWE-20 such as CWE-1284. If there is a calculation error for buffer sizes, consider CWE-131 or similar.
+ Notes

Relationship

At the code level, stack-based and heap-based overflows do not differ significantly, so there usually is not a need to distinguish them. From the attacker perspective, they can be quite different, since different techniques are required to exploit them.

Terminology

Many issues that are now called "buffer overflows" are substantively different than the "classic" overflow, including entirely different bug types that rely on overflow exploit techniques, such as integer signedness errors, integer overflows, and format string bugs. This imprecise terminology can make it difficult to determine which variant is being reported.
+ Taxonomy Mappings
Mapped Taxonomy Name Node ID Fit Mapped Node Name
PLOVER Unbounded Transfer ('classic overflow')
7 Pernicious Kingdoms Buffer Overflow
CLASP Buffer overflow
OWASP Top Ten 2004 A1 CWE More Specific Unvalidated Input
OWASP Top Ten 2004 A5 CWE More Specific Buffer Overflows
CERT C Secure Coding STR31-C Exact Guarantee that storage for strings has sufficient space for character data and the null terminator
WASC 7 Buffer Overflow
Software Fault Patterns SFP8 Faulty Buffer Access
OMG ASCSM ASCSM-CWE-120
OMG ASCRM ASCRM-CWE-120
+ References
[REF-7] Michael Howard and David LeBlanc. "Writing Secure Code". Chapter 5, "Public Enemy #1: The Buffer Overrun" Page 127. 2nd Edition. Microsoft Press. 2002-12-04. <https://www.microsoftpressstore.com/store/writing-secure-code-9780735617223>.
[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 5: Buffer Overruns." Page 89. McGraw-Hill. 2010.
[REF-56] Microsoft. "Using the Strsafe.h Functions". <https://learn.microsoft.com/en-us/windows/win32/menurc/strsafe-ovw?redirectedfrom=MSDN>. URL validated: 2023-04-07.
[REF-57] Matt Messier and John Viega. "Safe C String Library v1.0.3". <http://www.gnu-darwin.org/www001/ports-1.5a-CURRENT/devel/safestr/work/safestr-1.0.3/doc/safestr.html>. URL validated: 2023-04-07.
[REF-58] Michael Howard. "Address Space Layout Randomization in Windows Vista". <https://learn.microsoft.com/en-us/archive/blogs/michael_howard/address-space-layout-randomization-in-windows-vista>. URL validated: 2023-04-07.
[REF-59] Arjan van de Ven. "Limiting buffer overflows with ExecShield". <https://archive.is/saAFo>. URL validated: 2023-04-07.
[REF-60] "PaX". <https://en.wikipedia.org/wiki/Executable_space_protection#PaX>. URL validated: 2023-04-07.
[REF-74] Jason Lam. "Top 25 Series - Rank 3 - Classic Buffer Overflow". SANS Software Security Institute. 2010-03-02. <http://software-security.sans.org/blog/2010/03/02/top-25-series-rank-3-classic-buffer-overflow/>.
[REF-61] Microsoft. "Understanding DEP as a mitigation technology part 1". <https://msrc.microsoft.com/blog/2009/06/understanding-dep-as-a-mitigation-technology-part-1/>. URL validated: 2023-04-07.
[REF-76] Sean Barnum and Michael Gegick. "Least Privilege". 2005-09-14. <https://web.archive.org/web/20211209014121/https://www.cisa.gov/uscert/bsi/articles/knowledge/principles/least-privilege>. URL validated: 2023-04-07.
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 3, "Nonexecutable Stack", Page 76. 1st Edition. Addison Wesley. 2006.
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 5, "Protection Mechanisms", Page 189. 1st Edition. Addison Wesley. 2006.
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 8, "C String Handling", Page 388. 1st Edition. Addison Wesley. 2006.
[REF-64] Grant Murphy. "Position Independent Executables (PIE)". Red Hat. 2012-11-28. <https://www.redhat.com/en/blog/position-independent-executables-pie>. URL validated: 2023-04-07.
[REF-961] Object Management Group (OMG). "Automated Source Code Reliability Measure (ASCRM)". ASCRM-CWE-120. 2016-01. <http://www.omg.org/spec/ASCRM/1.0/>.
[REF-962] Object Management Group (OMG). "Automated Source Code Security Measure (ASCSM)". ASCSM-CWE-120. 2016-01. <http://www.omg.org/spec/ASCSM/1.0/>.
[REF-1332] John Richard Moser. "Prelink and address space randomization". 2006-07-05. <https://lwn.net/Articles/190139/>. URL validated: 2023-04-26.
[REF-1333] Dmitry Evtyushkin, Dmitry Ponomarev, Nael Abu-Ghazaleh. "Jump Over ASLR: Attacking Branch Predictors to Bypass ASLR". 2016. <http://www.cs.ucr.edu/~nael/pubs/micro16.pdf>. URL validated: 2023-04-26.