CWE-252: Unchecked Return Value
Description
The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.
Two common programmer assumptions are this function call can never fail and it doesn't matter if this function call fails. If an attacker can force the function to fail or otherwise return a value that is not expected, then the subsequent program logic could lead to a vulnerability, because the product is not in a state that the programmer assumes. For example, if the program calls a function to drop privileges but does not check the return code to ensure that privileges were successfully dropped, then the program will continue to operate with the higher privileges.
- Abstraction
- BaseA weakness specific enough to point to detection and prevention methods.
- Likelihood of exploit
- Low
- Status
- Draft
Common consequences
- AvailabilityIntegrity
Unexpected State; DoS: Crash, Exit, or Restart
An unexpected return value could place the system in a state that could lead to a crash or other unintended behaviors.
Potential mitigations
- ImplementationEffectiveness: High
Check the results of all functions that return a value and verify that the value is expected.
- Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Implementation
Ensure that you account for all possible return values from the function.
- Implementation
When designing a function, make sure you return a value or throw an exception in case of an error.
Related weaknesses
Parent weaknesses
Child weaknesses
Can lead to
CAPEC attack patterns that exploit it
CWE 4.20 links no CAPEC attack pattern to this weakness.