filesys

The server implements robust path validation including symbolic link resolution using `filepath.EvalSymlinks()` to prevent traversal attacks. It enforces canonical path checking against a list of explicitly allowed directories, preventing `../` traversal and prefix matching attacks (e.g., `/allowed` vs `/allowed_attacker`). Non-existent paths for write operations are validated by checking their parent directory chains. Broken symbolic links are explicitly blocked. All access denial attempts are logged with a 'SECURITY:' prefix for monitoring. Allowed directories are configured via an environment variable, preventing hardcoded paths. While highly secure, no system is entirely impervious to all theoretical attack vectors, hence a 9/10.