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Common Weakness Enumeration

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Home > CWE List > CWE-822: Untrusted Pointer Dereference (4.16)  
ID

CWE-822: Untrusted Pointer Dereference

Weakness ID: 822
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.
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+ Description
The product obtains a value from an untrusted source, converts this value to a pointer, and dereferences the resulting pointer.
+ Extended Description

An attacker can supply a pointer for memory locations that the product is not expecting. If the pointer is dereferenced for a write operation, the attack might allow modification of critical state variables, cause a crash, or execute code. If the dereferencing operation is for a read, then the attack might allow reading of sensitive data, cause a crash, or set a variable to an unexpected value (since the value will be read from an unexpected memory location).

There are several variants of this weakness, including but not necessarily limited to:

  • The untrusted value is directly invoked as a function call.
  • In OS kernels or drivers where there is a boundary between "userland" and privileged memory spaces, an untrusted pointer might enter through an API or system call (see CWE-781 for one such example).
  • Inadvertently accepting the value from an untrusted control sphere when it did not have to be accepted as input at all. This might occur when the code was originally developed to be run by a single user in a non-networked environment, and the code is then ported to or otherwise exposed to a networked environment.
+ 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

If the untrusted pointer is used in a read operation, an attacker might be able to read sensitive portions of memory.
Availability

Technical Impact: DoS: Crash, Exit, or Restart

If the untrusted pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" or larger than expected by a read or write operation, the application may terminate unexpectedly.
Integrity
Confidentiality
Availability

Technical Impact: Execute Unauthorized Code or Commands; Modify Memory

If the untrusted pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
+ 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
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. 781 Improper Address Validation in IOCTL with METHOD_NEITHER I/O Control Code
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. 125 Out-of-bounds Read
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. 787 Out-of-bounds Write
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
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
+ Observed Examples
Reference Description
message-passing framework interprets values in packets as pointers, causing a crash.
labeled as a "type confusion" issue, also referred to as a "stale pointer." However, the bug ID says "contents are simply interpreted as a pointer... renderer ordinarily doesn't supply this pointer directly". The "handle" in the untrusted area is replaced in one function, but not another - thus also, effectively, exposure to wrong sphere (CWE-668).
Untrusted dereference using undocumented constructor.
An error code is incorrectly checked and interpreted as a pointer, leading to a crash.
An untrusted value is obtained from a packet and directly called as a function pointer, leading to code execution.
Undocumented attribute in multimedia software allows "unmarshaling" of an untrusted pointer.
ActiveX control for security software accepts a parameter that is assumed to be an initialized pointer.
Spreadsheet software treats certain record values that lead to "user-controlled pointer" (might be untrusted offset, not untrusted pointer).
+ 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. 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. 876 CERT C++ Secure Coding Section 08 - Memory Management (MEM)
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. 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.
+ Notes

Terminology

Many weaknesses related to pointer dereferences fall under the general term of "memory corruption" or "memory safety." As of September 2010, there is no commonly-used terminology that covers the lower-level variants.

Maintenance

There are close relationships between incorrect pointer dereferences and other weaknesses related to buffer operations. There may not be sufficient community agreement regarding these relationships. Further study is needed to determine when these relationships are chains, composites, perspective/layering, or other types of relationships. As of September 2010, most of the relationships are being captured as chains.
+ Content History
+ Submissions
Submission Date Submitter Organization
2010-09-22
(CWE 1.10, 2010-09-27)
CWE Content Team MITRE
+ Modifications
Modification Date Modifier Organization
2011-03-29 CWE Content Team MITRE
updated Description
2011-06-01 CWE Content Team MITRE
updated Common_Consequences
2011-06-27 CWE Content Team MITRE
updated Related_Attack_Patterns, Relationships
2011-09-13 CWE Content Team MITRE
updated Relationships, Taxonomy_Mappings
2012-05-11 CWE Content Team MITRE
updated Relationships
2017-11-08 CWE Content Team MITRE
updated Taxonomy_Mappings
2019-06-20 CWE Content Team MITRE
updated Related_Attack_Patterns
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
2022-04-28 CWE Content Team MITRE
updated Research_Gaps
2023-01-31 CWE Content Team MITRE
updated Common_Consequences, Description
2023-04-27 CWE Content Team MITRE
updated Relationships
2023-06-29 CWE Content Team MITRE
updated Mapping_Notes
Page Last Updated: November 19, 2024