Description
The product accepts path input in the form of single dot directory exploit ('/./') 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-2024-6091 | Chain: AI agent platform does not restrict pathnames containing internal "/./" sequences (CWE-55), leading to an incomplete denylist (CWE-184) that does not prevent OS command injection (CWE-78) |
| CVE-2000-0004 | Server allows remote attackers to read source code for executable files by inserting a . (dot) into the URL. |
| CVE-2002-0304 | Server allows remote attackers to read password-protected files via a /./ in the HTTP request. |
| CVE-1999-1083 | Possibly (could be a cleansing error) |
| CVE-2004-0815 | "/./////etc" cleansed to ".///etc" then "/etc" |
| CVE-2002-0112 | Server allows remote attackers to view password protected files via /./ in the URL. |
Related Weaknesses
Taxonomy Mappings
- PLOVER: — /./ (single dot directory)
- Software Fault Patterns: SFP16 — Path Traversal
Frequently Asked Questions
What is CWE-55?
CWE-55 (Path Equivalence: '/./' (Single Dot Directory)) 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 single dot directory exploit ('/./') without appropriate validation, which can lead to ambiguous path resolution and allow an attacker to traverse the fil...
How can CWE-55 be exploited?
Attackers can exploit CWE-55 (Path Equivalence: '/./' (Single Dot Directory)) to read files or directories, modify files or directories. This weakness is typically introduced during the Implementation phase of software development.
How do I prevent CWE-55?
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-55?
CWE-55 is classified as a Variant-level weakness (Low-Medium abstraction). It has been observed in 6 real-world CVEs.