COMMON WEAKNESS ENUMERATIONDraft

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.

Abstraction

Base

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

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.

Root cause

How and when does the problem arise?

Lifecycle phase

Implementation

Risk

What does successful exploitation lead to?

Modify MemoryRead MemoryModify Application DataRead Application DataAlter Execution Logic

Affected security scopes: Integrity, Confidentiality, Other

Defence

How is it prevented and fixed?

Implementation

Implementation-phase defence

Detail
Use reentrant functions if available.

Implementation

Implementation-phase defence

Detail
Add synchronization to your non-reentrant function.

Implementation

Implementation-phase defence

Detail
In Java, use the ReentrantLock Class.

Verification

How is it detected?

Automated Static Analysis

High
Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)