Path Equivalence: 'filename....' (Multiple Trailing Dot)

Path equivalence vulnerabilities like this one trick the system's path resolution logic. When an application fails to normalize or validate a path like 'document....', different layers of the operating system or application framework may interpret it differently. This ambiguity can allow an attacker to escape restricted directories and traverse the file system to read, write, or delete sensitive files they shouldn't have access to. To prevent this, developers should implement strict input validation and canonicalize all user-supplied paths before use. Use built-in security functions to resolve paths to their absolute, normalized form, and enforce a whitelist of permitted directories. Never trust user input for file operations without first stripping potentially dangerous sequences and verifying the final path resides within the intended safe location.