CWE-463: Deletion of Data Structure Sentinel

Extended Description

Often times data-structure sentinels are used to mark structure of the data structure. A common example of this is the null character at the end of strings. Another common example is linked lists which may contain a sentinel to mark the end of the list. It is dangerous to allow this type of control data to be easily accessible. Therefore, it is important to protect from the deletion or modification outside of some wrapper interface which provides safety.

Code Examples & CVEs

Demonstrative Examples

This example creates a null terminated string and prints it contents.

The string foo has space for 9 characters and a null terminator, but 10 characters are written to it. As a result, the string foo is not null terminated and calling printf() on it will have unpredictable and possibly dangerous results.

BadC

char *foo;int counter;foo=calloc(sizeof(char)*10);                      for (counter=0;counter!=10;counter++) {foo[counter]='a';                      printf("%s\n",foo);}

Source-backed guidance

Additional facts reviewed against primary or authoritative security sources.

Verify controls for CWE-463 with SSDF evidence

Use NIST SSDF verification and vulnerability-response practices to detect CWE-463, Deletion of Data Structure Sentinel, 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

Apply Compilation or Build Hardening controls for Deletion of Data Structure Sentinel

MITRE associates mitigation with Architecture and Design, Build and Compilation, and Operation; the listed strategies include Compilation or Build Hardening; recorded impacts include Other. Use these source-defined anchors to turn CWE-463 into implementation, review, and verification checks for the affected component.

CWE-463: Deletion of Data Structure Sentinel — MITRE CWE

Triage CWE-463 against known exploitation evidence

Use CISA's Known Exploited Vulnerabilities catalog to test whether a vulnerability mapped to CWE-463, Deletion of Data Structure Sentinel, 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-463

Apply MITRE's full root-cause mapping guidance when using CWE-463, Deletion of Data Structure Sentinel. 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-463 with root-cause mapping checks

Apply MITRE's root-cause mapping quick tips to CWE-463, Deletion of Data Structure Sentinel. 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-463: Deletion of Data Structure Sentinel?+

CWE-463: Deletion of Data Structure Sentinel is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The accidental deletion of a data-structure sentinel can cause serious programming logic problems. Often times data-structure sentinels are used to mark structure of the data structure. A common example of this is the null character at the end of strings. Another common example is linked lists which may contain a sentinel to mark the end of the list. It is dangerous to allow this type of control data to be easily accessible. Therefore, it is important to protect from the deletion or modification outside of some wrapper interface which provides safety.

What are the security consequences of Deletion of Data Structure Sentinel?+

If exploited, CWE-463 (Deletion of Data Structure Sentinel) it can compromise Availability, Other and Authorization, leading to outcomes such as Other.

How do you prevent or mitigate Deletion of Data Structure Sentinel?+

Recommended mitigations for CWE-463 include: Use an abstraction library to abstract away risky APIs. Not a complete solution. Use OS-level preventative functionality. Not a complete solution.

Which programming languages are affected by Deletion of Data Structure Sentinel?+

CWE-463 commonly affects C and C++. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

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

A CWE (Common Weakness Enumeration) like CWE-463 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-463: Deletion of Data Structure Sentinel

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