| Impact | Details |
|---|---|
|
Modify Memory; Execute Unauthorized Code or Commands |
Scope: Integrity
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
|
|
DoS: Crash, Exit, or Restart |
Scope: Availability
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
|
|
Unexpected State |
Scope: Other
Subsequent write operations can produce undefined or unexpected results.
|
| Phase(s) | Mitigation |
|---|---|
|
Requirements |
Strategy: Language Selection Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe. |
|
Architecture and Design |
Strategy: Libraries or Frameworks Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions. Note:
This is not a complete solution, since many buffer overflows are not related to strings.
|
|
Operation; Build and Compilation |
Strategy: Environment Hardening Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail. Effectiveness: Defense in Depth Note:
This is not necessarily a complete solution, since these mechanisms only detect certain types of overflows. In addition, the result is still a denial of service, since the typical response is to exit the application. |
|
Implementation |
Consider adhering to the following rules when allocating and managing an application's memory:
|
|
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 |
|
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.
|
|
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 |
| 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. | 120 | Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
| 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. | 121 | Stack-based Buffer Overflow |
| 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. | 122 | Heap-based Buffer Overflow |
| 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. | 123 | Write-what-where Condition |
| 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') |
| 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. | 822 | Untrusted Pointer Dereference |
| 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. | 823 | Use of Out-of-range Pointer Offset |
| 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. | 824 | Access of Uninitialized Pointer |
| 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. | 825 | Expired Pointer Dereference |
| 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 |
| 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 |
| 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. | 120 | Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
| 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. | 123 | Write-what-where Condition |
| 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. | 120 | Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
| Phase | Note |
|---|---|
| Implementation |
C (Often Prevalent)
C++ (Often Prevalent)
Class: Assembly (Undetermined Prevalence)
Class: ICS/OT (Often Prevalent)
Example 1
The following code attempts to save four different identification numbers into an array.
Since the array is only allocated to hold three elements, the valid indices are 0 to 2; so, the assignment to id_sequence[3] is out of bounds.
Example 2
In the following code, it is possible to request that memcpy move a much larger segment of memory than assumed:
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
This code takes an IP address from the user and verifies that it is well formed. It then looks up the hostname and copies it into a buffer.
This function allocates a buffer of 64 bytes to store the hostname. 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 4
This code applies an encoding procedure to an input string and stores it into a buffer.
The programmer attempts to encode the ampersand character in the user-controlled string. However, the length of the string is validated before the encoding procedure is applied. Furthermore, the programmer assumes encoding expansion will only expand a given character by a factor of 4, while the encoding of the ampersand expands by 5. As a result, when the encoding procedure expands the string it is possible to overflow the destination buffer if the attacker provides a string of many ampersands.
Example 5
In the following C/C++ code, 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.
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 6
The following code allocates memory for a maximum number of widgets. It then gets a user-specified number of widgets, making sure that the user does not request too many. It then initializes the elements of the array using InitializeWidget(). Because the number of widgets can vary for each request, the code inserts a NULL pointer to signify the location of the last widget.
However, this code contains an off-by-one calculation error (CWE-193). It allocates exactly enough space to contain the specified number of widgets, but it does not include the space for the NULL pointer. As a result, the allocated buffer is smaller than it is supposed to be (CWE-131). So if the user ever requests MAX_NUM_WIDGETS, there is an out-of-bounds write (CWE-787) when the NULL is assigned. Depending on the environment and compilation settings, this could cause memory corruption.
Example 7
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.
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.
Note: this is a curated list of examples for users to understand the variety of ways in which this weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.
| Reference | Description |
|---|---|
|
The reference implementation code for a Trusted Platform Module does not implement length checks on data, allowing for an attacker to write 2 bytes past the end of a buffer.
|
|
|
GPU kernel driver allows memory corruption because a user can obtain read/write access to read-only pages, as exploited in the wild per CISA KEV.
|
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|
Out-of-bounds write in kernel-mode driver, as exploited in the wild per CISA KEV.
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Escape from browser sandbox using out-of-bounds write due to incorrect bounds check, as exploited in the wild per CISA KEV.
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Memory corruption in web browser scripting engine, as exploited in the wild per CISA KEV.
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malformed inputs cause accesses of uninitialized or previously-deleted objects, leading to memory corruption
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chain: -1 value from a function call was intended to indicate an error, but is used as an array index instead.
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Unchecked length of SSLv2 challenge value leads to buffer underflow.
|
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Buffer underflow from a small size value with a large buffer (length parameter inconsistency, CWE-130)
|
|
|
Classic stack-based buffer overflow in media player using a long entry in a playlist
|
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|
Heap-based buffer overflow in media player using a long entry in a playlist
|
| Ordinality | Description |
|---|---|
|
Resultant
|
(where the weakness is typically related to the presence of some other weaknesses)
At the point when the product writes data to an invalid location, it is likely that a separate weakness already occurred earlier. For example, the product might alter an index, perform incorrect pointer arithmetic, initialize or release memory incorrectly, etc., thus referencing a memory location outside the buffer.
|
| Method | Details |
|---|---|
|
Automated Static Analysis |
This weakness can often be detected using automated static analysis tools. Many modern tools use data flow analysis or constraint-based techniques to minimize the number of false positives. Automated static analysis generally does not account for environmental considerations when reporting out-of-bounds memory operations. This can make it difficult for users to determine which warnings should be investigated first. For example, an analysis tool might report buffer overflows that originate from command line arguments in a program that is not expected to run with setuid or other special privileges. Effectiveness: High Note:Detection techniques for buffer-related errors are more mature than for most other weakness types. |
|
Automated Dynamic Analysis |
This weakness can be detected using dynamic tools and techniques that interact with the software using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The software's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
|
| 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). | 1200 | Weaknesses in the 2019 CWE Top 25 Most Dangerous Software Errors |
| MemberOf | ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). | 1337 | Weaknesses in the 2021 CWE Top 25 Most Dangerous Software Weaknesses |
| MemberOf | ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). | 1350 | Weaknesses in the 2020 CWE Top 25 Most Dangerous Software Weaknesses |
| MemberOf | CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. | 1366 | ICS Communications: Frail Security in Protocols |
| MemberOf | ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). | 1387 | Weaknesses in the 2022 CWE Top 25 Most Dangerous Software Weaknesses |
| MemberOf | CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic. | 1399 | Comprehensive Categorization: Memory Safety |
| MemberOf | ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). | 1425 | Weaknesses in the 2023 CWE Top 25 Most Dangerous Software Weaknesses |
| MemberOf | ViewView - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). | 1430 | Weaknesses in the 2024 CWE Top 25 Most Dangerous Software Weaknesses |
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.| Mapped Taxonomy Name | Node ID | Fit | Mapped Node Name |
|---|---|---|---|
| ISA/IEC 62443 | Part 3-3 | Req SR 3.5 | |
| ISA/IEC 62443 | Part 4-1 | Req SI-1 | |
| ISA/IEC 62443 | Part 4-1 | Req SI-2 | |
| ISA/IEC 62443 | Part 4-1 | Req SVV-1 | |
| ISA/IEC 62443 | Part 4-1 | Req SVV-3 | |
| ISA/IEC 62443 | Part 4-2 | Req CR 3.5 |
| Submissions | ||
|---|---|---|
| Submission Date | Submitter | Organization |
|
2009年10月21日
(CWE 1.6, 2009年10月29日) |
CWE Content Team | MITRE |
| Contributions | ||
| Contribution Date | Contributor | Organization |
| 2023年04月25日 | "Mapping CWE to 62443" Sub-Working Group | CWE-CAPEC ICS/OT SIG |
| Suggested mappings to ISA/IEC 62443. | ||
|
2024年02月29日
(CWE 4.15, 2024年07月16日) |
Abhi Balakrishnan | |
| Provided diagram to improve CWE usability | ||
| Modifications | ||
| Modification Date | Modifier | Organization |
|
2025年09月09日
(CWE 4.18, 2025年09月09日) |
CWE Content Team | MITRE |
| updated Affected_Resources, Functional_Areas, References | ||
|
2025年04月03日
(CWE 4.17, 2025年04月03日) |
CWE Content Team | MITRE |
| updated Observed_Examples, Relationships | ||
|
2024年11月19日
(CWE 4.16, 2024年11月19日) |
CWE Content Team | MITRE |
| updated Observed_Examples, Relationships | ||
|
2024年07月16日
(CWE 4.15, 2024年07月16日) |
CWE Content Team | MITRE |
| updated Alternate_Terms, Common_Consequences, Description, Diagram, Weakness_Ordinalities | ||
|
2024年02月29日
(CWE 4.14, 2024年02月29日) |
CWE Content Team | MITRE |
| updated Demonstrative_Examples | ||
| 2023年06月29日 | CWE Content Team | MITRE |
| updated Mapping_Notes, Relationships, Taxonomy_Mappings | ||
| 2023年04月27日 | CWE Content Team | MITRE |
| updated Potential_Mitigations, References, Relationships, Taxonomy_Mappings | ||
| 2023年01月31日 | CWE Content Team | MITRE |
| updated Alternate_Terms, Demonstrative_Examples, Description | ||
| 2022年10月13日 | CWE Content Team | MITRE |
| updated Applicable_Platforms | ||
| 2022年06月28日 | CWE Content Team | MITRE |
| updated Observed_Examples, Relationships | ||
| 2021年07月20日 | CWE Content Team | MITRE |
| updated Demonstrative_Examples, Potential_Mitigations, Relationships | ||
| 2021年03月15日 | CWE Content Team | MITRE |
| updated Demonstrative_Examples | ||
| 2020年12月10日 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2020年08月20日 | CWE Content Team | MITRE |
| updated Alternate_Terms, Demonstrative_Examples, Observed_Examples, Relationships | ||
| 2020年06月25日 | CWE Content Team | MITRE |
| updated Observed_Examples | ||
| 2020年02月24日 | CWE Content Team | MITRE |
| updated Observed_Examples, Relationships | ||
| 2019年09月19日 | CWE Content Team | MITRE |
| updated Applicable_Platforms, Demonstrative_Examples, Detection_Factors, Likelihood_of_Exploit, Observed_Examples, Potential_Mitigations, References, Relationships, Time_of_Introduction | ||
| 2018年03月27日 | CWE Content Team | MITRE |
| updated Description | ||
| 2015年12月07日 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2014年06月23日 | CWE Content Team | MITRE |
| updated Demonstrative_Examples | ||
| 2011年06月01日 | CWE Content Team | MITRE |
| updated Common_Consequences | ||
| 2010年09月27日 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2010年02月16日 | CWE Content Team | MITRE |
| updated Demonstrative_Examples | ||
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