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Home > CWE List > CWE-824: Access of Uninitialized Pointer (4.18)
ID
CWE Glossary Definition

CWE-824: Access of Uninitialized Pointer

Weakness ID: 824
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 accesses or uses a pointer that has not been initialized.
Extended Description

If the pointer contains an uninitialized value, then the value might not point to a valid memory location. This could cause the product to read from or write to unexpected memory locations, leading to a denial of service. If the uninitialized pointer is used as a function call, then arbitrary functions could be invoked. If an attacker can influence the portion of uninitialized memory that is contained in the pointer, this weakness could be leveraged to execute code or perform other attacks.

Depending on memory layout, associated memory management behaviors, and product operation, the attacker might be able to influence the contents of the uninitialized pointer, thus gaining more fine-grained control of the memory location to be accessed.

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.
Impact Details

Read Memory

Scope: Confidentiality

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

DoS: Crash, Exit, or Restart

Scope: Availability

If the uninitialized pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.

Execute Unauthorized Code or Commands

Scope: Integrity, Confidentiality, Availability

If the uninitialized 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" (View-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
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
Relevant to the view "Software Development" (View-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
Relevant to the view "Weaknesses for Simplified Mapping of Published Vulnerabilities" (View-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
Relevant to the view "CISQ Quality Measures (2020)" (View-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
Relevant to the view "CISQ Data Protection Measures" (View-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
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)

Selected Observed Examples

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
LLM product has a free of an uninitialized pointer
Chain: secure communications library does not initialize a local variable for a data structure (CWE-456), leading to access of an uninitialized pointer (CWE-824).
Chain: C union member is not initialized (CWE-456), leading to access of invalid pointer (CWE-824)
chain: unchecked return value (CWE-252) leads to free of invalid, uninitialized pointer (CWE-824).
Pointer in structure is not initialized, leading to NULL pointer dereference (CWE-476) and system crash.
Free of an uninitialized pointer.
Improper handling of invalid signatures leads to free of invalid pointer.
Invalid encoding triggers free of uninitialized pointer.
Crafted PNG image leads to free of uninitialized pointer.
Crafted GIF image leads to free of uninitialized pointer.
Access of uninitialized pointer might lead to code execution.
Step-based manipulation: invocation of debugging function before the primary initialization function leads to access of an uninitialized pointer and code execution.
Unchecked return values can lead to a write to an uninitialized pointer.
zero-length input leads to free of uninitialized pointer.
Crafted font leads to uninitialized function pointer.
Uninitialized function pointer in freed memory is invoked
LDAP server mishandles malformed BER queries, leading to free of uninitialized memory
Firewall can crash with certain ICMP packets that trigger access of an uninitialized pointer.
LDAP server does not initialize members of structs, which leads to free of uninitialized pointer if an LDAP request fails.
Detection Methods
Method Details

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
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. 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.
References
[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 7, "Variable Initialization", Page 312. 1st Edition. Addison Wesley. 2006.
Content History
Submissions
Submission Date Submitter Organization
2010年09月22日
(CWE 1.10, 2010年09月27日) 		CWE Content Team MITRE
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
2025年04月03日
(CWE 4.17, 2025年04月03日) 		CWE Content Team MITRE
updated Applicable_Platforms, Observed_Examples
2024年07月16日
(CWE 4.15, 2024年07月16日) 		CWE Content Team MITRE
updated Observed_Examples
2023年06月29日 CWE Content Team MITRE
updated Mapping_Notes
2023年04月27日 CWE Content Team MITRE
updated Detection_Factors, Relationships
2023年01月31日 CWE Content Team MITRE
updated Common_Consequences, Description
2022年04月28日 CWE Content Team MITRE
updated Research_Gaps
2020年12月10日 CWE Content Team MITRE
updated Relationships
2020年08月20日 CWE Content Team MITRE
updated Relationships
2020年02月24日 CWE Content Team MITRE
updated Relationships
2015年12月07日 CWE Content Team MITRE
updated Relationships
2012年05月11日 CWE Content Team MITRE
updated References
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Page Last Updated: September 09, 2025

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