CWE - CWE-366: Race Condition within a Thread (4.18)

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CWE Glossary Definition

CWE-366: Race Condition within a Thread

Weakness ID: 366

Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.

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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.

Common Consequences

Section HelpThis table specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

Impact	Details
Alter Execution Logic; Unexpected State	Scope: Integrity, Other The main problem is that -- if a lock is overcome -- data could be altered in a bad state.

Potential Mitigations

Phase(s)	Mitigation
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.
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.

Relationships

Section Help This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

Relevant to the view "Research Concepts" (View-1000)

Nature	Type	ID	Name
ChildOf	Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	362	Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Relevant to the view "Software Development" (View-699)

Nature	Type	ID	Name
MemberOf	Category Category - a CWE entry that contains a set of other entries that share a common characteristic.	557	Concurrency Issues

Relevant to the view "CISQ Quality Measures (2020)" (View-1305)

Nature	Type	ID	Name
ChildOf	Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	662	Improper Synchronization

Relevant to the view "CISQ Data Protection Measures" (View-1340)

Nature	Type	ID	Name
ChildOf	Class Class - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.	662	Improper Synchronization

Modes Of Introduction

Section HelpThe different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

Phase	Note
Implementation

Applicable Platforms

Section HelpThis listing shows possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

C (Undetermined Prevalence)

C++ (Undetermined Prevalence)

Java (Undetermined Prevalence)

C# (Undetermined Prevalence)

Likelihood Of Exploit

Medium

Demonstrative Examples

Example 1

The following example demonstrates the weakness.

(bad code)

Example Language: C

int foo = 0;
int storenum(int num) {

static int counter = 0;
counter++;
if (num > foo) foo = num;
return foo;

}

(bad code)

Example Language: Java

public classRace {

static int foo = 0;
public static void main() {

new Threader().start();
foo = 1;

}
public static class Threader extends Thread {

public void run() {

System.out.println(foo);

}

Selected Observed Examples

Note: this is a curated list of examples for users to understand the variety of ways in which this weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.

Reference	Description
CVE-2022-2621	Chain: two threads in a web browser use the same resource (CWE-366), but one of those threads can destroy the resource before the other has completed (CWE-416).

Detection Methods

Method	Details
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.) Effectiveness: High

Method

Details

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.)

Effectiveness: High

Affected Resources

System Process

Memberships

Section HelpThis MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.

Nature	Type	ID	Name
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	748	CERT C Secure Coding Standard (2008) Appendix - POSIX (POS)
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	852	The CERT Oracle Secure Coding Standard for Java (2011) Chapter 9 - Visibility and Atomicity (VNA)
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	882	CERT C++ Secure Coding Section 14 - Concurrency (CON)
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	986	SFP Secondary Cluster: Missing Lock
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	1142	SEI CERT Oracle Secure Coding Standard for Java - Guidelines 08. Visibility and Atomicity (VNA)
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	1169	SEI CERT C Coding Standard - Guidelines 14. Concurrency (CON)
MemberOf	CategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.	1401	Comprehensive Categorization: Concurrency

Vulnerability Mapping Notes

Usage ALLOWED

(this CWE ID may be used to map to real-world vulnerabilities)

Reason Acceptable-Use

Rationale

This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.

Comments

Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Taxonomy Mappings

Mapped Taxonomy Name	Node ID	Fit	Mapped Node Name
CLASP	Race condition within a thread
CERT C Secure Coding	CON32-C	CWE More Abstract	Prevent data races when accessing bit-fields from multiple threads
CERT C Secure Coding	CON40-C	CWE More Abstract	Do not refer to an atomic variable twice in an expression
CERT C Secure Coding	CON43-C	Exact	Do not allow data races in multithreaded code
The CERT Oracle Secure Coding Standard for Java (2011)	VNA02-J	Ensure that compound operations on shared variables are atomic
The CERT Oracle Secure Coding Standard for Java (2011)	VNA03-J	Do not assume that a group of calls to independently atomic methods is atomic
Software Fault Patterns	SFP19	Missing Lock

Related Attack Patterns

CAPEC-ID	Attack Pattern Name
CAPEC-26	Leveraging Race Conditions
CAPEC-29	Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions

References

[REF-18] Secure Software, Inc.. "The CLASP Application Security Process". 2005.
<https://cwe.mitre.org/documents/sources/TheCLASPApplicationSecurityProcess.pdf>. (URL validated: 2024年11月17日)

[REF-44] Michael Howard, David LeBlanc and John Viega. "24 Deadly Sins of Software Security". "Sin 13: Race Conditions." Page 205. McGraw-Hill. 2010.

[REF-62] Mark Dowd, John McDonald and Justin Schuh. "The Art of Software Security Assessment". Chapter 13, "Race Conditions", Page 759. 1st Edition. Addison Wesley. 2006.

Content History

Submissions
Submission Date	Submitter	Organization
2006年07月19日 (CWE Draft 3, 2006年07月19日)	CLASP
2006年07月19日 (CWE Draft 3, 2006年07月19日)
Modifications
Modification Date	Modifier	Organization
2023年10月26日	CWE Content Team	MITRE
2023年10月26日	updated Observed_Examples
2023年06月29日	CWE Content Team	MITRE
2023年06月29日	updated Mapping_Notes
2023年04月27日	CWE Content Team	MITRE
2023年04月27日	updated Detection_Factors, Relationships, Time_of_Introduction
2022年04月28日	CWE Content Team	MITRE
2022年04月28日	updated Relationships
2021年03月15日	CWE Content Team	MITRE
2021年03月15日	updated Potential_Mitigations
2020年12月10日	CWE Content Team	MITRE
2020年12月10日	updated Relationships
2020年08月20日	CWE Content Team	MITRE
2020年08月20日	updated Relationships
2020年02月24日	CWE Content Team	MITRE
2020年02月24日	updated References, Relationships
2019年01月03日	CWE Content Team	MITRE
2019年01月03日	updated Relationships, Taxonomy_Mappings
2017年11月08日	CWE Content Team	MITRE
2017年11月08日	updated Demonstrative_Examples, Relationships, Taxonomy_Mappings
2014年07月30日	CWE Content Team	MITRE
2014年07月30日	updated Relationships, Taxonomy_Mappings
2012年05月11日	CWE Content Team	MITRE
2012年05月11日	updated References, Relationships
2011年09月13日	CWE Content Team	MITRE
2011年09月13日	updated Relationships, Taxonomy_Mappings
2011年06月27日	CWE Content Team	MITRE
2011年06月27日	updated Common_Consequences
2011年06月01日	CWE Content Team	MITRE
2011年06月01日	updated Common_Consequences, Relationships, Taxonomy_Mappings
2010年09月27日	CWE Content Team	MITRE
2010年09月27日	updated Potential_Mitigations, Relationships
2008年11月24日	CWE Content Team	MITRE
2008年11月24日	updated Relationships, Taxonomy_Mappings
2008年09月08日	CWE Content Team	MITRE
2008年09月08日	updated Applicable_Platforms, Common_Consequences, Relationships, Taxonomy_Mappings
2008年07月01日	Eric Dalci	Cigital
2008年07月01日	updated Time_of_Introduction

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Page Last Updated: September 09, 2025

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