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Deletion of Data Structure Sentinel

Incomplete Base
Structure: Simple
Description

The accidental deletion of a data-structure sentinel can cause serious programming logic problems.

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.
Common Consequences 2
Scope: AvailabilityOther

Impact: Other

Generally this error will cause the data structure to not work properly.

Scope: AuthorizationOther

Impact: Other

If a control character, such as NULL is removed, one may cause resource access control problems.
Potential Mitigations 3
Phase: Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Phase: Build and Compilation

Strategy: Compilation or Build Hardening

Run or compile the software using features or extensions that automatically provide a protection mechanism that mitigates or eliminates buffer overflows. For example, certain compilers and extensions provide automatic buffer overflow detection mechanisms that are built into the compiled code. Examples include the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice.

Effectiveness: Defense in Depth

Phase: Operation
Use OS-level preventative functionality. Not a complete solution.
Demonstrative Examples 1
This example creates a null terminated string and prints it contents.

Code Example:

Bad
C
c
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.
References 2
The CLASP Application Security Process
Secure Software, Inc.
2005
https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf(2024-11-17)
ID: REF-18
The Art of Software Security Assessment
Mark Dowd, John McDonald, and Justin Schuh
Addison Wesley
2006
ID: REF-62
Applicable Platforms
Languages:
C : UndeterminedC++ : Undetermined
Modes of Introduction
Implementation
Related Weaknesses
ChildOf: Improper Neutralization (CWE-707)
PeerOf: Addition of Data Structure Sentinel (CWE-464)
Taxonomy Mapping
  • CLASP