A software system that accepts path input in the form of single dot directory exploit ('/./') without appropriate validation can lead to ambiguous path resolution and allow an attacker to traverse the file system to unintended locations or access arbitrary files.
Time of Introduction
Technical Impact: Read files or
directories; Modify files or
Server allows remote attackers to view password
protected files via /./ in the URL.
Strategy: Input Validation
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 whitelist validation schemes by introducing dangerous inputs after they have been checked.