Read Time:1 Minute, 3 Second
Description
The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize ‘…’ (triple dot) sequences that can resolve to a location that is outside of that directory.
Modes of Introduction:
– Implementation
Related Weaknesses
CWE-23
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-2001-0480
- read of arbitrary files and directories using GET or CD with “…” in Windows-based FTP server.
- CVE-2002-0288
- read files using “.” and Unicode-encoded “/” or “” characters in the URL.
