CWE-366

Base Abstraction Level
Pillar — Highest-level weakness category
Class — Abstract, language-independent
Base — Specific enough to detect
Variant — Tied to specific technology
Compound — Requires multiple weaknesses Draft MITRE CWE Status
Stable — Fully reviewed and complete
Draft — Under development, may change
Incomplete — Partially defined by MITRE
Deprecated — No longer recommended
Obsolete — Replaced by another CWE Exploit: Medium
Race Condition within a Thread

Description

If two threads of execution use a resource simultaneously, there exists the possibility that resources may be used while invalid, in turn making the state of execution undefined.

Consequences

Integrity, Other — Alter Execution Logic, Unexpected State

The main problem is that -- if a lock is overcome -- data could be altered in a bad state.

Mitigations

Phase: Architecture and Design

Use locking functionality. This is the recommended solution. Implement some form of locking mechanism around code which alters or reads persistent data in a multithreaded environment.

Phase: Architecture and Design

Create resource-locking validation checks. If no inherent locking mechanisms exist, use flags and signals to enforce your own blocking scheme when resources are being used by other threads of execution.

Detection

Automated Static Analysis

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.)