CWE-825: Expired Pointer Dereference

Extended Description

When a product releases memory, but it maintains a pointer to that memory, then the memory might be re-allocated at a later time. If the original pointer is accessed to read or write data, then this could cause the product to read or modify data that is in use by a different function or process. Depending on how the newly-allocated memory is used, this could lead to a denial of service, information exposure, or code execution.

Code Examples & CVEs

Demonstrative Examples

The following code shows a simple example of a use after free error:

When an error occurs, the pointer is immediately freed. However, this pointer is later incorrectly used in the logError function.

BadC

char* ptr = (char*)malloc (SIZE);if (err) {abrt = 1;free(ptr);}...if (abrt) {logError("operation aborted before commit", ptr);}

The following code shows a simple example of a double free error:

Double free vulnerabilities have two common (and sometimes overlapping) causes:

BadC

char* ptr = (char*)malloc (SIZE);...if (abrt) {free(ptr);}...free(ptr);

Observed CVE Examples (5)

CVE-2023-26463

Chain: IPSec VPN product uses the same variable for multiple purposes in the same function (CWE-1109), leading to incorrect access control (CWE-284) and expired pointer dereference (CWE-825)

View Details

CVE-2008-5013

access of expired memory address leads to arbitrary code execution

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CVE-2010-3257

stale pointer issue leads to denial of service and possibly other consequences

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CVE-2008-0062

Chain: a message having an unknown message type may cause a reference to uninitialized memory resulting in a null pointer dereference (CWE-476) or dangling pointer (CWE-825), possibly crashing the system or causing heap corruption.

View Details

CVE-2007-1211

read of value at an offset into a structure after the offset is no longer valid

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Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-825 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-825, Expired Pointer Dereference, throughout the product lifecycle. Derive review questions, static or dynamic checks, and negative tests from the CWE's causal behavior; define the components and lifecycle stages each check covers; and retain findings with enough evidence to distinguish the root cause from symptoms and impacts. Track escapes and false negatives, then improve the verification plan after every confirmed occurrence.

NIST SP 800-218 Secure Software Development Framework — National Institute of Standards and Technology

Address Expired Pointer Dereference during Architecture and Design

MITRE associates mitigation with Architecture and Design, and Implementation; documented detection approaches include Automated Static Analysis, and Automated Dynamic Analysis; recorded impacts include Read Memory, DoS: Crash, Exit, or Restart, and Execute Unauthorized Code or Commands. Use these source-defined anchors to turn CWE-825 into implementation, review, and verification checks for the affected component.

CWE-825: Expired Pointer Dereference — MITRE CWE

Triage CWE-825 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-825, Expired Pointer Dereference, has evidence of exploitation in the wild. Confirm the CVE-to-CWE root-cause mapping independently before attaching the example, then capture the affected product, required action, and remediation deadline. A missing KEV match is not evidence that the weakness is unexploited, and a KEV entry must not be generalized to every occurrence of this CWE.

Known Exploited Vulnerabilities Catalog — Cybersecurity and Infrastructure Security Agency

Apply precise root-cause mapping to CWE-825

Apply MITRE's full root-cause mapping guidance when using CWE-825, Expired Pointer Dereference. Separate weakness language from attacker prerequisites and technical impact, check the entry's abstraction and vulnerability-mapping notes, and prefer the most specific Base or Variant supported by the evidence. Record the rejected alternatives and require an independent review before the mapping is used for remediation trends or program metrics.

CVE to CWE Root Cause Mapping Guidance — MITRE CWE

Validate CWE-825 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-825, Expired Pointer Dereference. Confirm the finding describes the causal weakness rather than an impact or attack pattern, compare the abstraction and mapping notes with plausible alternatives, and have a second reviewer challenge the selection. Preserve the evidence and reasoning so recurring defects can be measured against one consistent identifier.

CVE to CWE Root Cause Mapping Quick Tips — MITRE CWE

Frequently Asked Questions

What is CWE-825: Expired Pointer Dereference?+

CWE-825: Expired Pointer Dereference is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product dereferences a pointer that contains a location for memory that was previously valid, but is no longer valid. When a product releases memory, but it maintains a pointer to that memory, then the memory might be re-allocated at a later time. If the original pointer is accessed to read or write data, then this could cause the product to read or modify data that is in use by a different function or process. Depending on how the newly-allocated memory is used, this could lead to a denial of service, information exposure, or code execution.

What are the security consequences of Expired Pointer Dereference?+

If exploited, CWE-825 (Expired Pointer Dereference) it can compromise Confidentiality, Availability and Integrity, leading to outcomes such as Read Memory, DoS: Crash, Exit, or Restart and Execute Unauthorized Code or Commands.

How do you prevent or mitigate Expired Pointer Dereference?+

Recommended mitigations for CWE-825 include: Choose a language that provides automatic memory management. When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

Which programming languages are affected by Expired Pointer Dereference?+

CWE-825 commonly affects C, C++ and Memory-Unsafe. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

What are real-world examples of Expired Pointer Dereference?+

MITRE documents real CVEs mapped to CWE-825, including CVE-2023-26463, CVE-2008-5013, CVE-2010-3257, CVE-2008-0062 and CVE-2007-1211. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.

What is the difference between a CWE and a CVE?+

A CWE (Common Weakness Enumeration) like CWE-825 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.

CWE-825: Expired Pointer Dereference

Extended Description

Technical Details

Applicable To

Security Consequences

Scope

Impact

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Impact

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Impact

Mitigation Strategies

Phase

Description

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Detection Methods

Code Examples & CVEs

Demonstrative Examples

Observed CVE Examples (5)

CWE Relationships

Parent Weaknesses

Source-backed guidance

Verify controls for CWE-825 with SSDF evidence

Address Expired Pointer Dereference during Architecture and Design

Triage CWE-825 against known exploitation evidence

Apply precise root-cause mapping to CWE-825

Validate CWE-825 with root-cause mapping checks

Frequently Asked Questions

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