Improper Restriction of Operations within the Bounds of a Memory Buffer (4.15) (original) (raw)
| CWE Glossary Definition |  |
|---|---|
Weakness ID: 119
Vulnerability Mapping: DISCOURAGEDThis CWE ID should not be used to map to real-world vulnerabilities
Abstraction: ClassClass - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.
Description
| 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. |  |
|---|
Extended Description
Certain languages allow direct addressing of memory locations and do not automatically ensure that these locations are valid for the memory buffer that is being referenced. This can cause read or write operations to be performed on memory locations that may be associated with other variables, data structures, or internal program data.
Alternate Terms
| Buffer Overflow: | This term has many different meanings to different audiences. From a CWE mapping perspective, this term should be avoided where possible. Some researchers, developers, and tools intend for it to mean "write past the end of a buffer," whereas others use the same term to mean "any read or write outside the boundaries of a buffer, whether before the beginning of the buffer or after the end of the buffer." Others could mean "any action after the end of a buffer, whether it is a read or write." Since the term is commonly used for exploitation and for vulnerabilities, it further confuses things. |
|---|---|
| buffer overrun: | Some prominent vendors and researchers use the term "buffer overrun," but most people use "buffer overflow." See the alternate term for "buffer overflow" for context. |
| memory safety: | Generally used for techniques that avoid weaknesses related to memory access, such as those identified by CWE-119 and its descendants. However, the term is not formal, and there is likely disagreement between practitioners as to which weaknesses are implicitly covered by the "memory safety" term. |
Common Consequences
This table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
| Scope | Impact | Likelihood |
|---|---|---|
| IntegrityConfidentialityAvailability | Technical Impact: _Execute Unauthorized Code or Commands; Modify Memory_If the memory accessible by the attacker can be effectively controlled, it may be possible to execute arbitrary code, as with a standard buffer overflow. If the attacker can overwrite a pointer's worth of memory (usually 32 or 64 bits), they can alter the intended control flow by redirecting a function pointer to their own malicious code. Even when the attacker can only modify a single byte arbitrary code execution can be possible. Sometimes this is because the same problem can be exploited repeatedly to the same effect. Other times it is because the attacker can overwrite security-critical application-specific data -- such as a flag indicating whether the user is an administrator. | |
| AvailabilityConfidentiality | Technical Impact: _Read Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)_Out of bounds memory access will very likely result in the corruption of relevant memory, and perhaps instructions, possibly leading to a crash. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop. | |
| Confidentiality | Technical Impact: _Read Memory_In the case of 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. |
Potential Mitigations
| Phase: RequirementsStrategy: Language SelectionUse 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 DesignStrategy: Libraries or FrameworksUse 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 CompilationStrategy: Environment HardeningUse 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 DepthNote: 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: ImplementationConsider 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. |
| Phases: Operation; Build and CompilationStrategy: Environment HardeningRun 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 DepthNote: 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: OperationStrategy: Environment HardeningUse 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 DepthNote: 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. |
| Phase: ImplementationReplace unbounded copy functions with analogous functions that support length arguments, such as strcpy with strncpy. Create these if they are not available. Effectiveness: ModerateNote: 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). |
Relationships
This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
Relevant to the view "Research Concepts" (CWE-1000)
| Nature | Type | ID | Name |
|---|---|---|---|
| ChildOf |  Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. |
118 | Incorrect Access of Indexable Resource ('Range Error') |
| ParentOf |  Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
120 | Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
125 | Out-of-bounds Read |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
466 | Return of Pointer Value Outside of Expected Range |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
786 | Access of Memory Location Before Start of Buffer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
787 | Out-of-bounds Write |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
788 | Access of Memory Location After End of Buffer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
805 | Buffer Access with Incorrect Length Value |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
822 | Untrusted Pointer Dereference |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
823 | Use of Out-of-range Pointer Offset |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
824 | Access of Uninitialized Pointer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
825 | Expired Pointer Dereference |
| CanFollow | Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource. |
20 | Improper Input Validation |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
128 | Wrap-around Error |
| CanFollow |  Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource. |
129 | Improper Validation of Array Index |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
131 | Incorrect Calculation of Buffer Size |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
190 | Integer Overflow or Wraparound |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
193 | Off-by-one Error |
| CanFollow | Variant - a weakness that is linked to a certain type of product, typically involving a specific language or technology. More specific than a Base weakness. Variant level weaknesses typically describe issues in terms of 3 to 5 of the following dimensions: behavior, property, technology, language, and resource. |
195 | Signed to Unsigned Conversion Error |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
839 | Numeric Range Comparison Without Minimum Check |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
843 | Access of Resource Using Incompatible Type ('Type Confusion') |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
1257 | Improper Access Control Applied to Mirrored or Aliased Memory Regions |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
1260 | Improper Handling of Overlap Between Protected Memory Ranges |
| CanFollow | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
1339 | Insufficient Precision or Accuracy of a Real Number |
This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (CWE-1003)
| Nature | Type | ID | Name |
|---|---|---|---|
| MemberOf |  View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries). |
1003 | Weaknesses for Simplified Mapping of Published Vulnerabilities |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
120 | Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
125 | Out-of-bounds Read |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
787 | Out-of-bounds Write |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
824 | Access of Uninitialized Pointer |
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 |
|---|---|---|---|
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
120 | Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
123 | Write-what-where Condition |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
125 | Out-of-bounds Read |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
130 | Improper Handling of Length Parameter Inconsistency |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
786 | Access of Memory Location Before Start of Buffer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
787 | Out-of-bounds Write |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
788 | Access of Memory Location After End of Buffer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
805 | Buffer Access with Incorrect Length Value |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
822 | Untrusted Pointer Dereference |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
823 | Use of Out-of-range Pointer Offset |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
824 | Access of Uninitialized Pointer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
825 | Expired Pointer Dereference |
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 |
|---|---|---|---|
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
120 | Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
123 | Write-what-where Condition |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
125 | Out-of-bounds Read |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
130 | Improper Handling of Length Parameter Inconsistency |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
786 | Access of Memory Location Before Start of Buffer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
787 | Out-of-bounds Write |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
788 | Access of Memory Location After End of Buffer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
805 | Buffer Access with Incorrect Length Value |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
822 | Untrusted Pointer Dereference |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
823 | Use of Out-of-range Pointer Offset |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
824 | Access of Uninitialized Pointer |
| ParentOf | Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource. |
825 | Expired Pointer Dereference |
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 - 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 |
Background Details
Certain languages allow direct addressing of memory locations and do not automatically ensure that these locations are valid for the memory buffer that is being referenced.
Modes Of Introduction
The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.
| Phase | Note |
|---|---|
| Implementation |
Applicable Platforms
This listing shows possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.
Languages
C (Often Prevalent)
C++ (Often Prevalent)
Class: Assembly (Undetermined Prevalence)
Likelihood Of Exploit
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: C
void host_lookup(char *user_supplied_addr){
struct hostent *hp;
in_addr_t *addr;
char hostname[64];
in_addr_t inet_addr(const char *cp);
/*routine that ensures user_supplied_addr is in the right format for conversion */
validate_addr_form(user_supplied_addr);
addr = inet_addr(user_supplied_addr);
hp = gethostbyaddr( addr, sizeof(struct in_addr), AF_INET);
strcpy(hostname, hp->h_name);
}
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 2
This example applies an encoding procedure to an input string and stores it into a buffer.
(bad code)
Example Language: C
char * copy_input(char *user_supplied_string){
int i, dst_index;
char *dst_buf = (char*)malloc(4*sizeof(char) * MAX_SIZE);
if ( MAX_SIZE <= strlen(user_supplied_string) ){
die("user string too long, die evil hacker!");
}
dst_index = 0;
for ( i = 0; i < strlen(user_supplied_string); i++ ){
if( '&' == user_supplied_string[i] ){
dst_buf[dst_index++] = '&';
dst_buf[dst_index++] = 'a';
dst_buf[dst_index++] = 'm';
dst_buf[dst_index++] = 'p';
dst_buf[dst_index++] = ';';
}
else if ('<' == user_supplied_string[i] ){
/* encode to < */
}
else dst_buf[dst_index++] = user_supplied_string[i];
}
return dst_buf;
}
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 3
The following example asks a user for an offset into an array to select an item.
(bad code)
Example Language: C
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 4
In the following code, the method retrieves a value from an array at a specific array index location that is given as an input parameter to the method
(bad code)
Example Language: C
int getValueFromArray(int *array, int len, int index) {
int value;
// check that the array index is less than the maximum
// length of the array
if (index < len) {
// get the value at the specified index of the array
value = array[index];
}
// if array index is invalid then output error message
// and return value indicating error
else {
printf("Value is: %d\n", array[index]);
value = -1;
}
return value;
}
However, this method only verifies that the given array index is less than the maximum length of the array but does not check for the minimum value (CWE-839). This will allow a negative value to be accepted as the input array index, which will result in a out of bounds read (CWE-125) and may allow access to sensitive memory. The input array index should be checked to verify that is within the maximum and minimum range required for the array (CWE-129). In this example the if statement should be modified to include a minimum range check, as shown below.
(good code)
Example Language: C
...
// check that the array index is within the correct
// range of values for the array
if (index >= 0 && index < len) {
...
Example 5
Windows provides the _mbs family of functions to perform various operations on multibyte strings. When these functions are passed a malformed multibyte string, such as a string containing a valid leading byte followed by a single null byte, they can read or write past the end of the string buffer causing a buffer overflow. The following functions all pose a risk of buffer overflow: _mbsinc _mbsdec _mbsncat _mbsncpy _mbsnextc _mbsnset _mbsrev _mbsset _mbsstr _mbstok _mbccpy _mbslen
Observed Examples
| Reference | Description |
|---|---|
| CVE-2021-22991 | Incorrect URI normalization in application traffic product leads to buffer overflow, as exploited in the wild per CISA KEV. |
| CVE-2020-29557 | Buffer overflow in Wi-Fi router web interface, as exploited in the wild per CISA KEV. |
| CVE-2009-2550 | Classic stack-based buffer overflow in media player using a long entry in a playlist |
| CVE-2009-2403 | Heap-based buffer overflow in media player using a long entry in a playlist |
| CVE-2009-0689 | large precision value in a format string triggers overflow |
| CVE-2009-0690 | negative offset value leads to out-of-bounds read |
| CVE-2009-1532 | malformed inputs cause accesses of uninitialized or previously-deleted objects, leading to memory corruption |
| CVE-2009-1528 | chain: lack of synchronization leads to memory corruption |
| CVE-2021-29529 | Chain: machine-learning product can have a heap-based buffer overflow (CWE-122) when some integer-oriented bounds are calculated by using ceiling() and floor() on floating point values (CWE-1339) |
| CVE-2009-0558 | attacker-controlled array index leads to code execution |
| CVE-2009-0269 | chain: -1 value from a function call was intended to indicate an error, but is used as an array index instead. |
| CVE-2009-0566 | chain: incorrect calculations lead to incorrect pointer dereference and memory corruption |
| CVE-2009-1350 | product accepts crafted messages that lead to a dereference of an arbitrary pointer |
| CVE-2009-0191 | chain: malformed input causes dereference of uninitialized memory |
| CVE-2008-4113 | OS kernel trusts userland-supplied length value, allowing reading of sensitive information |
| CVE-2005-1513 | Chain: integer overflow in securely-coded mail program leads to buffer overflow. In 2005, this was regarded as unrealistic to exploit, but in 2020, it was rediscovered to be easier to exploit due to evolutions of the technology. |
| CVE-2003-0542 | buffer overflow involving a regular expression with a large number of captures |
| CVE-2017-1000121 | chain: unchecked message size metadata allows integer overflow (CWE-190) leading to buffer overflow (CWE-119). |
Detection Methods
| Automated Static AnalysisThis 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: HighNote: Detection techniques for buffer-related errors are more mature than for most other weakness types. |
|---|
| Automated Dynamic AnalysisThis 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. |
| Automated Static Analysis - Binary or BytecodeAccording to SOAR, the following detection techniques may be useful: Cost effective for partial coverage: Binary / Bytecode Quality Analysis Bytecode Weakness Analysis - including disassembler + source code weakness analysis Binary Weakness Analysis - including disassembler + source code weakness analysis Effectiveness: SOAR Partial |
| Manual Static Analysis - Binary or BytecodeAccording 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 InterpretationAccording 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 InterpretationAccording 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 CodeAccording 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 CodeAccording to SOAR, the following detection techniques may be useful: Source code Weakness Analyzer Context-configured Source Code Weakness Analyzer Cost effective for partial coverage: Source Code Quality Analyzer Effectiveness: High |
| Architecture or Design ReviewAccording to SOAR, the following detection techniques may be useful: Formal Methods / Correct-By-Construction Cost effective for partial coverage: Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.) Effectiveness: High |
Affected Resources
- Memory
Memberships
This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.
Vulnerability Mapping Notes
| Usage: DISCOURAGED(this CWE ID should not be used to map to real-world vulnerabilities) |
|---|
| Reason: Frequent Misuse |
| Rationale: CWE-119 is commonly misused in low-information vulnerability reports when lower-level CWEs could be used instead, or when more details about the vulnerability are available. |
| Comments: Look at CWE-119's children and consider mapping to CWEs such as CWE-787: Out-of-bounds Write, CWE-125: Out-of-bounds Read, or others. |
Notes
Applicable Platform
It is possible in any programming languages without memory management support to attempt an operation outside of the bounds of a memory buffer, but the consequences will vary widely depending on the language, platform, and chip architecture.
Taxonomy Mappings
| Mapped Taxonomy Name | Node ID | Fit | Mapped Node Name |
|---|---|---|---|
| OWASP Top Ten 2004 | A5 | Exact | Buffer Overflows |
| CERT C Secure Coding | ARR00-C | Understand how arrays work | |
| CERT C Secure Coding | ARR30-C | CWE More Abstract | Do not form or use out-of-bounds pointers or array subscripts |
| CERT C Secure Coding | ARR38-C | CWE More Abstract | Guarantee that library functions do not form invalid pointers |
| CERT C Secure Coding | ENV01-C | Do not make assumptions about the size of an environment variable | |
| CERT C Secure Coding | EXP39-C | Imprecise | Do not access a variable through a pointer of an incompatible type |
| CERT C Secure Coding | FIO37-C | Do not assume character data has been read | |
| CERT C Secure Coding | STR31-C | CWE More Abstract | Guarantee that storage for strings has sufficient space for character data and the null terminator |
| CERT C Secure Coding | STR32-C | CWE More Abstract | Do not pass a non-null-terminated character sequence to a library function that expects a string |
| WASC | 7 | Buffer Overflow | |
| Software Fault Patterns | SFP8 | Faulty Buffer Access |
References
Content History
| Submissions |
||
|---|---|---|
| Submission Date | Submitter | Organization |
| 2006-07-19(CWE Draft 3, 2006-07-19) | PLOVER | |
| Contributions |
||
| Contribution Date | Contributor | Organization |
| 2024-02-29(CWE 4.15, 2024-07-16) | Abhi Balakrishnan | |
| Provided diagram to improve CWE usability | ||
| Modifications |
||
| Modification Date | Modifier | Organization |
| 2008-07-01 | Eric Dalci | Cigital |
| updated Time_of_Introduction | ||
| 2008-08-15 | Veracode | |
| Suggested OWASP Top Ten 2004 mapping | ||
| 2008-09-08 | CWE Content Team | MITRE |
| updated Description, Relationships, Taxonomy_Mappings | ||
| 2008-10-14 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2008-11-24 | CWE Content Team | MITRE |
| updated Relationships, Taxonomy_Mappings | ||
| 2009-01-12 | CWE Content Team | MITRE |
| updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Likelihood_of_Exploit, Name, Potential_Mitigations, References, Relationships | ||
| 2009-03-10 | CWE Content Team | MITRE |
| updated Potential_Mitigations | ||
| 2009-05-27 | CWE Content Team | MITRE |
| updated Demonstrative_Examples | ||
| 2009-07-27 | CWE Content Team | MITRE |
| updated Observed_Examples | ||
| 2009-10-29 | CWE Content Team | MITRE |
| updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Description, Relationships, Time_of_Introduction | ||
| 2009-12-28 | CWE Content Team | MITRE |
| updated Common_Consequences, Demonstrative_Examples, Detection_Factors, Observed_Examples | ||
| 2010-02-16 | CWE Content Team | MITRE |
| updated Alternate_Terms, Applicable_Platforms, Demonstrative_Examples, Detection_Factors, Potential_Mitigations, References, Relationships, Taxonomy_Mappings | ||
| 2010-06-21 | CWE Content Team | MITRE |
| updated Potential_Mitigations | ||
| 2010-09-27 | CWE Content Team | MITRE |
| updated Potential_Mitigations, Relationships | ||
| 2010-12-13 | CWE Content Team | MITRE |
| updated Name | ||
| 2011-03-29 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2011-06-01 | CWE Content Team | MITRE |
| updated Common_Consequences, Relationships | ||
| 2011-09-13 | CWE Content Team | MITRE |
| updated Relationships, Taxonomy_Mappings | ||
| 2012-05-11 | CWE Content Team | MITRE |
| updated Demonstrative_Examples, Potential_Mitigations, References, Relationships | ||
| 2012-10-30 | CWE Content Team | MITRE |
| updated Potential_Mitigations | ||
| 2013-02-21 | CWE Content Team | MITRE |
| updated Demonstrative_Examples | ||
| 2014-02-18 | CWE Content Team | MITRE |
| updated Potential_Mitigations, References | ||
| 2014-07-30 | CWE Content Team | MITRE |
| updated Detection_Factors, Relationships, Taxonomy_Mappings | ||
| 2015-12-07 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2017-01-19 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2017-05-03 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2017-11-08 | CWE Content Team | MITRE |
| updated Applicable_Platforms, Common_Consequences, Demonstrative_Examples, Observed_Examples, References, Relationships, 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, Relationships | ||
| 2019-09-19 | CWE Content Team | MITRE |
| updated References, Relationships | ||
| 2020-02-24 | CWE Content Team | MITRE |
| updated Relationships, Taxonomy_Mappings, Time_of_Introduction | ||
| 2020-06-25 | CWE Content Team | MITRE |
| updated Relationships | ||
| 2020-08-20 | CWE Content Team | MITRE |
| updated Alternate_Terms, Relationships | ||
| 2020-12-10 | CWE Content Team | MITRE |
| updated Alternate_Terms, Observed_Examples, Relationships | ||
| 2021-07-20 | CWE Content Team | MITRE |
| updated Demonstrative_Examples, Observed_Examples, Potential_Mitigations, Relationships | ||
| 2022-06-28 | CWE Content Team | MITRE |
| updated Observed_Examples, Relationships | ||
| 2022-10-13 | CWE Content Team | MITRE |
| updated Relationships, Taxonomy_Mappings | ||
| 2023-01-31 | CWE Content Team | MITRE |
| updated Alternate_Terms, Description | ||
| 2023-04-27 | CWE Content Team | MITRE |
| updated Potential_Mitigations, References, Relationships, Time_of_Introduction | ||
| 2023-06-29 | CWE Content Team | MITRE |
| updated Mapping_Notes, Relationships | ||
| 2024-07-16(CWE 4.15, 2024-07-16) | CWE Content Team | MITRE |
| updated Alternate_Terms, Background_Details, Common_Consequences, Description, Diagram | ||
| Previous Entry Names |
||
| Change Date | Previous Entry Name | |
| 2008-04-11 | Buffer Errors | |
| 2009-01-12 | Failure to Constrain Operations within the Bounds of an Allocated Memory Buffer | |
| 2010-12-13 | Failure to Constrain Operations within the Bounds of a Memory Buffer |
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