Description
The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize ‘…/…//’ (doubled triple dot slash) sequences that can resolve to a location that is outside of that directory.
Modes of Introduction:
– Implementation
Related Weaknesses
Consequences
Confidentiality, Integrity: Read Files or Directories, Modify Files or Directories
Potential Mitigations
Phase: Implementation
Effectiveness: High
Description:
Phase: Implementation
Description:
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.
CVE References
- CVE-2005-2169
- chain: “…/…//” bypasses protection mechanism using regexp’s that remove “../” resulting in collapse into an unsafe value “../” (CWE-182) and resultant path traversal.
- CVE-2005-0202
- “…/….///” bypasses regexp’s that remove “./” and “../”