Weakness · Medium
CWE-667: Improper Locking
What it is
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
- Severity (our rating)
- Medium
- Likelihood of exploit
- Not rated by MITRE
- Introduced during
- Architecture and Design, Implementation
- Exploited in the wild
- 2 known exploited CVEs
In more detail
Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.
What an attacker can do
- DoS: Resource Consumption (CPU) (Availability)
How to prevent it
Implementation
- Use industry standard APIs to implement locking mechanism.
How to find it
- 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.)
Exploited in the wild: 2 CVEs
Vulnerabilities caused by CWE-667 that attackers have used, from CISA's Known Exploited Vulnerabilities catalog, newest first.
H2 Security
Found it in your code?
We review where it appears, fix it with your team, and check it was not already used against you.
Talk to our teamT Academy
Stop writing it in the first place
Learn to build software and systems without weaknesses like this one, with practice on real hosts in your browser, every objective checked on the machine.
Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.