CWE-637: Unnecessary Complexity in Protection Mechanism (Not Using 'Economy of Mechanism')
CWE版本: 4.18
更新日期: 2025-09-09
弱点描述
The product uses a more complex mechanism than necessary, which could lead to resultant weaknesses when the mechanism is not correctly understood, modeled, configured, implemented, or used.
扩展描述
Security mechanisms should be as simple as possible. Complex security mechanisms may engender partial implementations and compatibility problems, with resulting mismatches in assumptions and implemented security. A corollary of this principle is that data specifications should be as simple as possible, because complex data specifications result in complex validation code. Complex tasks and systems may also need to be guarded by complex security checks, so simple systems should be preferred.
常见后果
影响范围: Other
技术影响: Other
潜在缓解措施
阶段: Architecture and Design
描述: Avoid complex security mechanisms when simpler ones would meet requirements. Avoid complex data models, and unnecessarily complex operations. Adopt architectures that provide guarantees, simplify understanding through elegance and abstraction, and that can be implemented similarly. Modularize, isolate and do not trust complex code, and apply other secure programming principles on these modules (e.g., least privilege) to mitigate vulnerabilities.
观察示例
参考: CVE-2007-6067
Support for complex regular expressions leads to a resultant algorithmic complexity weakness (CWE-407).
参考: CVE-2007-1552
Either a filename extension and a Content-Type header could be used to infer the file type, but the developer only checks the Content-Type, enabling unrestricted file upload (CWE-434).
参考: CVE-2007-6479
In Apache environments, a "filename.php.gif" can be redirected to the PHP interpreter instead of being sent as an image/gif directly to the user. Not knowing this, the developer only checks the last extension of a submitted filename, enabling arbitrary code execution.
参考: CVE-2005-2148
The developer cleanses the $_REQUEST superglobal array, but PHP also populates $_GET, allowing attackers to bypass the protection mechanism and conduct SQL injection attacks against code that uses $_GET.
引入模式
| 阶段 | 说明 |
|---|---|
| Architecture and Design | - |
| Implementation | - |
| Operation | - |