CWE-543: Use of Singleton Pattern Without Synchronization in a Multithreaded Context
The product uses the singleton pattern when creating a resource within a multithreaded environment.
How it's found
Use of Singleton Pattern Without Synchronization in a Multithreaded Context is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.
The use of a singleton pattern may not be thread-safe.
Consequences
- Other, Modify Application Data
Mitigations
- Architecture and Design: Use the Thread-Specific Storage Pattern. See References.
- Implementation: Do not use member fields to store information in the Servlet. In multithreading environments, storing user data in Servlet member fields introduces a data access race condition.
- Implementation: Avoid using the double-checked locking pattern in language versions that cannot guarantee thread safety. This pattern may be used to avoid the overhead of a synchronized call, but in certain versions of Java (for example), this has been shown to be unsafe because it still introduces a race condition (CWE-209).
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-543?
The product uses the singleton pattern when creating a resource within a multithreaded environment.
How do you find Use of Singleton Pattern Without Synchronization in a Multithreaded Context?
Use of Singleton Pattern Without Synchronization in a Multithreaded Context is a specific, narrowly defined instance of a broader pattern. Testers confirm it with targeted code review and a proof-of-concept input that exercises the exact code path this weakness describes.
What is the impact of CWE-543?
Other, Modify Application Data
Does TurboPentest test for Use of Singleton Pattern Without Synchronization in a Multithreaded 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