CWE-41: Improper Resolution of Path Equivalence

Base Incomplete Simple

CWE版本: 4.18

更新日期: 2025-09-09

弱点描述

The product is vulnerable to file system contents disclosure through path equivalence. Path equivalence involves the use of special characters in file and directory names. The associated manipulations are intended to generate multiple names for the same object.

扩展描述

Path equivalence is usually employed in order to circumvent access controls expressed using an incomplete set of file name or file path representations. This is different from path traversal, wherein the manipulations are performed to generate a name for a different object.

常见后果

影响范围: Confidentiality Integrity Access Control

技术影响: Read Files or Directories Modify Files or Directories Bypass Protection Mechanism

说明: An attacker may be able to traverse the file system to unintended locations and read or overwrite the contents of unexpected files. If the files are used for a security mechanism than an attacker may be able to bypass the mechanism.

潜在缓解措施

阶段: Implementation

策略: Input Validation

阶段: Implementation

策略: Output Encoding

描述: Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.

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.

检测方法

方法: Automated Static Analysis - Binary or Bytecode

有效性: SOAR Partial

方法: Manual Static Analysis - Binary or Bytecode

有效性: SOAR Partial

方法: Dynamic Analysis with Automated Results Interpretation

有效性: SOAR Partial

方法: Dynamic Analysis with Manual Results Interpretation

有效性: SOAR Partial

方法: Manual Static Analysis - Source Code

有效性: High

方法: Automated Static Analysis - Source Code

有效性: SOAR Partial

方法: Architecture or Design Review

有效性: High

观察示例

参考: CVE-2000-1114

Source code disclosure using trailing dot

参考: CVE-2002-1986

Source code disclosure using trailing dot

参考: CVE-2004-2213

Source code disclosure using trailing dot or trailing encoding space "%20"

参考: CVE-2005-3293

Source code disclosure using trailing dot

参考: CVE-2004-0061

Bypass directory access restrictions using trailing dot in URL

参考: CVE-2000-1133

Bypass directory access restrictions using trailing dot in URL

参考: CVE-2001-1386

Bypass check for ".lnk" extension using ".lnk."

参考: CVE-2001-0693