CWE-57: Path Equivalence: 'fakedir/../realdir/filename'
CWE版本: 4.18
更新日期: 2025-09-09
弱点描述
The product contains protection mechanisms to restrict access to 'realdir/filename', but it constructs pathnames using external input in the form of 'fakedir/../realdir/filename' that are not handled by those mechanisms. This allows attackers to perform unauthorized actions against the targeted file.
常见后果
影响范围: Confidentiality Integrity
技术影响: Read Files or Directories Modify Files or Directories
潜在缓解措施
阶段: Implementation
策略: Input Validation
描述: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
观察示例
参考: CVE-2001-1152
Proxy allows remote attackers to bypass denylist restrictions and connect to unauthorized web servers by modifying the requested URL, including (1) a // (double slash), (2) a /SUBDIR/.. where the desired file is in the parentdir, (3) a /./, or (4) URL-encoded characters.
参考: CVE-2000-0191
application check access for restricted URL before canonicalization
参考: CVE-2005-1366
CGI source disclosure using "dirname/../cgi-bin"
引入模式
| 阶段 | 说明 |
|---|---|
| Implementation | - |
适用平台
编程语言
分类映射
| 分类名称 | 条目ID | 条目名称 | 映射适配度 |
|---|---|---|---|
| PLOVER | - | dirname/fakechild/../realchild/filename | - |
| Software Fault Patterns | SFP16 | Path Traversal | - |