CWE-821: Incorrect Synchronization

What is Incorrect Synchronization?

• Overview: Incorrect Synchronization (CWE-821) occurs when a software product accesses a shared resource in a concurrent environment without properly synchronizing access, leading to potential inconsistencies and unexpected behavior.

• Exploitation Methods:

• Attackers can exploit this vulnerability by causing race conditions where the timing of operations is manipulated to achieve unintended outcomes.
• Common attack patterns include timing attacks, where the attacker influences execution sequences, and data races, where concurrent processes access and modify shared data simultaneously.

• Security Impact:

• Direct consequences include data corruption, application crashes, and erratic behavior due to inconsistent resource states.
• Potential cascading effects involve further security vulnerabilities, such as privilege escalation, where attackers obtain unauthorized access to sensitive operations.
• Business impact can be significant, including data loss, reduced trust in the software, and potential financial losses from downtime or data breaches.

• Prevention Guidelines:

• Specific code-level fixes include using proper synchronization mechanisms like mutexes, semaphores, or locks to ensure that only one thread accesses a resource at a time.
• Security best practices involve designing software with concurrency in mind, performing thorough testing for race conditions, and using thread-safe libraries.
• Recommended tools and frameworks include static analysis tools to detect synchronization issues and using languages or frameworks that provide built-in concurrency control features, such as Java's synchronized blocks or Python's threading module.

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Technical Details

Likelihood of Exploit: Not specified

Affected Languages: Not specified

Affected Technologies: Not specified