Unchecked Return Value

Opis

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.

Skutki

• Availability, Integrity

  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.

Zapobieganie

• Implementation

  Check the results of all functions that return a value and verify that the value is expected.

  Skuteczność: High

• 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 [REF-1484].

• 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.

Przykłady podatności

• CVE-2020-17533 Chain: unchecked return value (CWE-252) of some functions for policy enforcement leads to authorization bypass (CWE-862)
• CVE-2020-6078 Chain: The return value of a function returning a pointer is not checked for success (CWE-252) resulting in the later use of an uninitialized variable (CWE-456) and a null pointer dereference (CWE-476)
• CVE-2019-15900 Chain: sscanf() call is used to check if a username and group exists, but the return value of sscanf() call is not checked (CWE-252), causing an uninitialized variable to be checked (CWE-457), returning success to allow authorization bypass for executing a privileged (CWE-863).
• CVE-2007-3798 Unchecked return value leads to resultant integer overflow and code execution.
• CVE-2006-4447 Program does not check return value when invoking functions to drop privileges, which could leave users with higher privileges than expected by forcing those functions to fail.
• CVE-2006-2916 Program does not check return value when invoking functions to drop privileges, which could leave users with higher privileges than expected by forcing those functions to fail.
• CVE-2008-5183 chain: unchecked return value can lead to NULL dereference
• CVE-2010-0211 chain: unchecked return value (CWE-252) leads to free of invalid, uninitialized pointer (CWE-824).
• CVE-2017-6964 Linux-based device mapper encryption program does not check the return value of setuid and setgid allowing attackers to execute code with unintended privileges.
• CVE-2002-1372 Chain: Return values of file/socket operations are not checked (CWE-252), allowing resultant consumption of file descriptors (CWE-772).

Słabość nadrzędna

• CWE-754 Improper Check for Unusual or Exceptional Conditions

Może prowadzić do

• CWE-476 NULL Pointer Dereference

Słabości podrzędne

• CWE-690 Unchecked Return Value to NULL Pointer Dereference

Kiedy powstaje

• Implementation

Dotyczy

Not Language-Specific

Źródła

1. Seven Pernicious Kingdoms: A Taxonomy of Software Security Errors — Katrina Tsipenyuk, Brian Chess, Gary McGraw, NIST, 2005
2. The Art of Software Security Assessment — Mark Dowd, John McDonald, Justin Schuh, Chapter 7, "Program Building Blocks" Page 341, Addison Wesley, 2006
3. Writing Secure Code — Michael Howard, David LeBlanc, Chapter 20, "Checking Returns" Page 624, Microsoft Press, 2002
4. 24 Deadly Sins of Software Security — Michael Howard, David LeBlanc, John Viega, "Sin 11: Failure to Handle Errors Correctly." Page 183, McGraw-Hill, 2010
5. Automated Source Code Reliability Measure (ASCRM) — Object Management Group (OMG), ASCRM-CWE-252-data, 2016
6. Automated Source Code Reliability Measure (ASCRM) — Object Management Group (OMG), ASCRM-CWE-252-resource, 2016
7. Automated Source Code Security Measure (ASCSM) — Object Management Group (OMG), ASCSM-CWE-252-resource, 2016
8. D3FEND: D3-NPC Null Pointer Checking — D3FEND