名称: Multiple Unlocks of a Critical Resource

The product unlocks a critical resource more times than intended, leading to an unexpected state in the system.

基本信息

引入方式

Implementation

适用平台

编程语言

类： Not Language-Specific (Undetermined)

常见后果

影响范围	影响	可能性
Availability Integrity	DoS: Crash, Exit, or Restart, Modify Memory, Unexpected State 注意： When the product is operating in a concurrent environment and repeatedly unlocks a critical resource, the consequences will vary based on the type of lock, the lock's implementation, and the resource being protected. In some situations such as with semaphores, the resources are pooled and extra calls to unlock will increase the count for the number of available resources, likely resulting in a crash or unpredictable behavior when the system nears capacity.

观察示例

参考资料	描述
CVE-2009-0935	Attacker provides invalid address to a memory-reading function, causing a mutex to be unlocked twice

潜在缓解措施

Phases : Implementation
When locking and unlocking a resource, try to be sure that all control paths through the code in which the resource is locked one or more times correspond to exactly as many unlocks. If the product acquires a lock and then determines it is not able to perform its intended behavior, be sure to release the lock(s) before waiting for conditions to improve. Reacquire the lock(s) before trying again.

检测方法

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.)
有效性 : High

漏洞映射说明

依据 : 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.
备注 : 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.

备注

An alternate way to think about this weakness is as an imbalance between the number of locks / unlocks in the control flow. Over the course of execution, if each lock call is not followed by a subsequent call to unlock in a reasonable amount of time, then system performance may be degraded or at least operating at less than peak levels if there is competition for the locks. This entry may need to be modified to reflect these concepts in the future.

提交记录

名称	组织	日期	发布日期	Version
CWE Content Team	MITRE	2009-03-03 +00:00	2009-05-27 +00:00	1.4

修改记录

名称	组织	日期	备注
CWE Content Team	MITRE	2011-06-01 +00:00	updated Common_Consequences
CWE Content Team	MITRE	2011-06-27 +00:00	updated Common_Consequences
CWE Content Team	MITRE	2012-05-11 +00:00	updated Relationships
CWE Content Team	MITRE	2014-07-30 +00:00	updated Relationships, Taxonomy_Mappings
CWE Content Team	MITRE	2019-06-20 +00:00	updated Type
CWE Content Team	MITRE	2020-02-24 +00:00	updated Relationships
CWE Content Team	MITRE	2023-01-31 +00:00	updated Description, Potential_Mitigations
CWE Content Team	MITRE	2023-04-27 +00:00	updated Relationships
CWE Content Team	MITRE	2023-06-29 +00:00	updated Mapping_Notes
CWE Content Team	MITRE	2025-12-11 +00:00	updated Applicable_Platforms, Detection_Factors, Weakness_Ordinalities
CWE Content Team	MITRE	2026-10-28 +00:00	updated Common_Consequences, Description

CWE-765 详情

CWE-765