CWE-563: Assignment to Variable without Use
CWE版本: 4.18
更新日期: 2025-09-09
弱点描述
The variable's value is assigned but never used, making it a dead store.
扩展描述
After the assignment, the variable is either assigned another value or goes out of scope. It is likely that the variable is simply vestigial, but it is also possible that the unused variable points out a bug.
常见后果
影响范围: Other
技术影响: Quality Degradation Varies by Context
说明: This weakness could be an indication of a bug in the program or a deprecated variable that was not removed and is an indication of poor quality. This could lead to further bugs and the introduction of weaknesses.
潜在缓解措施
阶段: Implementation
描述: Remove unused variables from the code.
检测方法
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
引入模式
| 阶段 | 说明 |
|---|---|
| Implementation | - |
分类映射
| 分类名称 | 条目ID | 条目名称 | 映射适配度 |
|---|---|---|---|
| CERT C Secure Coding | MSC00-C | Compile cleanly at high warning levels | - |
| SEI CERT Perl Coding Standard | MSC01-PL | Detect and remove unused variables | Imprecise |
| Software Fault Patterns | SFP2 | Unused Entities | - |