CWE-663: Use of a Non-reentrant Function in a Concurrent Context
The product calls a non-reentrant function in a concurrent context in which a competing code sequence (e.g. thread or signal handler) may have an opportunity to call the same function or otherwise influence its state.
How it's found
Use of a Non-reentrant Function in a Concurrent Context is typically found by tracing untrusted input from where it enters the system to the point where it is used without the check or neutralization this weakness describes, combining manual code review with dynamic testing.
Consequences
- Modify Memory, Read Memory, Modify Application Data, Read Application Data, Alter Execution Logic
Mitigations
- Implementation: Use reentrant functions if available.
- Implementation: Add synchronization to your non-reentrant function.
- Implementation: In Java, use the ReentrantLock Class.
Where this fits in a TurboPentest engagement
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
Frequently asked questions
What is CWE-663?
The product calls a non-reentrant function in a concurrent context in which a competing code sequence (e.g. thread or signal handler) may have an opportunity to call the same function or otherwise influence its state.
How do you find Use of a Non-reentrant Function in a Concurrent Context?
Use of a Non-reentrant Function in a Concurrent Context is typically found by tracing untrusted input from where it enters the system to the point where it is used without the check or neutralization this weakness describes, combining manual code review with dynamic testing.
What is the impact of CWE-663?
Modify Memory, Read Memory, Modify Application Data, Read Application Data, Alter Execution Logic
Does TurboPentest test for Use of a Non-reentrant Function in a Concurrent Context?
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
Related CWEs
Written and reviewed by
Michel Chamberland - Founder & CEO, IntegSec
CISSP, OSCP, OSCE, CEH, GIAC, CCSK · 20+ years in offensive security
Michel has spent 20+ years on offensive security teams including IBM X-Force Red and Trustwave SpiderLabs, leading penetration tests, red team engagements, and breach response for Fortune 500 customers. He is the founder of IntegSec and the architect of TurboPentest.
Find these issues before an attacker does
TurboPentest runs an agentic AI pentest against your target and reports findings with proof, from $99 per target.
Start a pentest