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CWE-567

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CWE-567

Unsynchronized Access to Shared Data in a Multithreaded Context

Base
Draft

Description

The product does not properly synchronize shared data, such as static variables across threads, which can lead to undefined behavior and unpredictable data changes.

{"xhtml:p":["Within servlets, shared static variables are not protected from concurrent access, but servlets are multithreaded. This is a typical programming mistake in J2EE applications, since the multithreading is handled by the framework. When a shared variable can be influenced by an attacker, one thread could wind up modifying the variable to contain data that is not valid for a different thread that is also using the data within the variable.","Note that this weakness is not unique to servlets."]}

Common Consequences

Scope

Confidentiality
Integrity
Availability

Impact

Read Application Data, Modify Application Data, DoS: Instability, DoS: Crash, Exit, or Restart

Potential Mitigations

Implementation

Remove the use of static variables used between servlets. If this cannot be avoided, use synchronized access for these variables.

Applicable Platforms

Java

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