Description
The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize ‘..filename’ (leading backslash dot dot) 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
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-2002-1987
- Protection mechanism checks for “/..” but doesn’t account for Windows-specific “..” allowing read of arbitrary files.
- CVE-2005-2142
- Directory traversal vulnerability in FTP server allows remote authenticated attackers to list arbitrary directories via a “..” sequence in an LS command.