CyberSecBulletin

Path Traversal: 'dir/../../filename'

CWE-27

The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize multiple internal../ sequences that can resolve to a location that is outside of that directory.

We track 17 vulnerabilities of this type. 100% are rated high or critical, and the average CVSS score is 8.3. 1 has been exploited in real attacks.

How this weakness is prevented

  • Implementation: 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.

Latest Path Traversal: 'dir/../../filename' vulnerabilities