Path Traversal: '...' (Triple Dot)

The triple dot sequence ('...') is a clever evasion technique that can bypass basic path traversal filters. On Windows systems, it's often interpreted as '..\..', allowing attackers to jump two directory levels at once. Many security checks only look for the standard double-dot ('..'), making this a simple yet effective way to slip past incomplete validations. This flaw often stems from overly simplistic filtering logic. For example, if a system only removes './' sequences from an input like '....//', the remaining characters can collapse back into a dangerous '..' path traversal payload. Developers need to implement robust path normalization and canonicalization before checking directory boundaries, rather than relying on blacklisting specific character patterns.