Description
The product accepts path input in the form of trailing backslash ('filedir\') without appropriate validation, which can lead to ambiguous path resolution and allow an attacker to traverse the file system to unintended locations or access arbitrary files.
Potential Impact
Confidentiality, Integrity
Read Files or Directories, Modify Files or Directories
Mitigations & Prevention
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.
Real-World CVE Examples
| CVE ID | Description |
|---|---|
| CVE-2004-0847 | web framework for .NET allows remote attackers to bypass authentication for .aspx files in restricted directories via a request containing a (1) "\" (backslash) or (2) "%5C" (encoded backslash) |
| CVE-2004-0061 | Bypass directory access restrictions using trailing dot in URL |
Related Weaknesses
Taxonomy Mappings
- PLOVER: — filedir\ (trailing backslash)
- Software Fault Patterns: SFP16 — Path Traversal
Frequently Asked Questions
What is CWE-54?
CWE-54 (Path Equivalence: 'filedir\' (Trailing Backslash)) is a software weakness identified by MITRE's Common Weakness Enumeration. It is classified as a Variant-level weakness. The product accepts path input in the form of trailing backslash ('filedir\') without appropriate validation, which can lead to ambiguous path resolution and allow an attacker to traverse the file sys...
How can CWE-54 be exploited?
Attackers can exploit CWE-54 (Path Equivalence: 'filedir\' (Trailing Backslash)) to read files or directories, modify files or directories. This weakness is typically introduced during the Implementation, Porting phase of software development.
How do I prevent CWE-54?
Key mitigations include: 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 (C
What is the severity of CWE-54?
CWE-54 is classified as a Variant-level weakness (Low-Medium abstraction). It has been observed in 2 real-world CVEs.