CWE-1096: Singleton Class Instance Creation without Proper Locking or Synchronization
The product implements a Singleton design pattern but does not use appropriate locking or other synchronization mechanism to ensure that the singleton class is only instantiated once.
How it's found
Singleton Class Instance Creation without Proper Locking or Synchronization 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.
Consequences
- Reduce Reliability: This issue can prevent the product from running reliably, e.g. by making the instantiation process non-thread-safe and introducing deadlock (CWE-833) or livelock conditions. If the relevant code is reachable by an attacker, then this reliability problem might introduce a vulnerability.
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-1096?
The product implements a Singleton design pattern but does not use appropriate locking or other synchronization mechanism to ensure that the singleton class is only instantiated once.
How do you find Singleton Class Instance Creation without Proper Locking or Synchronization?
Singleton Class Instance Creation without Proper Locking or Synchronization 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-1096?
Reduce Reliability: This issue can prevent the product from running reliably, e.g. by making the instantiation process non-thread-safe and introducing deadlock (CWE-833) or livelock conditions. If the relevant code is reachable by an attacker, then this reliability problem might introduce a vulnerability.
Does TurboPentest test for Singleton Class Instance Creation without Proper Locking or Synchronization?
This weakness is not covered by the automated black-box pentest. IntegSec pentesters cover it in a manual engagement.
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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.
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