Description
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.
Modes of Introduction:
– Architecture and Design
Related Weaknesses
Consequences
Availability, Other: Other
Generally this error will cause the data structure to not work properly.
Authorization, Other: Other
If a control character, such as NULL is removed, one may cause resource access control problems.
Potential Mitigations
Phase: Architecture and Design
Description:
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Phase: Build and Compilation
Effectiveness: Defense in Depth
Description:
This is not necessarily a complete solution, since these mechanisms can only detect certain types of overflows. In addition, an attack could still cause a denial of service, since the typical response is to exit the application.
Phase: Operation
Description:
Use OS-level preventative functionality. Not a complete solution.