CWE-252 is Unchecked Return Value. The flaw arises when the product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions. The database currently holds 39 vulnerabilities mapped to CWE-252 and none of them are in the CISA Known Exploited Vulnerabilities catalog.
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No vulnerability data in CISA KEV for CWE-252
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.
Many functions will return some value about the success of their actions. This will alert the program whether or not to handle any errors caused by that function.
| Impact | Scope | Explanation |
|---|---|---|
| Unexpected State, DoS: Crash, Exit, or Restart | Availability, Integrity | An unexpected return value could place the system in a state that could lead to a crash or other unintended behaviors. |
| Method | Approach | Effectiveness |
|---|---|---|
| Automated Static Analysis | Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.) | High |
Below are representative vulnerabilities related to this CWE, prioritized by severity.
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