CWE WEAKNESSES / CWE-662
CWE-662
Improper Synchronization
What it is
The product utilizes multiple threads, processes, components, or systems to allow temporary access to a shared resource that can only be exclusive to one process at a time, but it does not properly synchronize these actions, which might cause simultaneous accesses of this resource by multiple threads or processes.
Synchronization refers to a variety of behaviors and mechanisms that allow two or more independently-operating processes or threads to ensure that they operate on shared resources in predictable ways that do not interfere with each other. Some shared resource operations cannot be executed atomically; that is, multiple steps must be guaranteed to execute sequentially, without any interference by other processes. Synchronization mechanisms vary widely, but they may include locking, mutexes, and semaphores. When a multi-step operation on a shared resource cannot be guaranteed to execute independent of interference, then the resulting behavior can be unpredictable. Improper synchronization could lead to data or memory corruption, denial of service, etc.
Impact
| Integrity, Confidentiality, Other | Modify Application Data, Read Application Data, Alter Execution Logic |
Mitigations
- [Implementation] Use industry standard APIs to synchronize your code.
Real-world CVE examples
- CVE-2021-1782 — Chain: improper locking (CWE-667) leads to race condition (CWE-362), as exploited in the wild per CISA KEV.
- CVE-2009-0935 — Attacker provides invalid address to a memory-reading function, causing a mutex to be unlocked twice
Related weaknesses
Browse all common weaknesses, check related exploited CVEs, or map to ATT&CK techniques.
Source: MITRE CWE. View on cwe.mitre.org →