GHSA-q9m2-fhv9-3jcf

## Summary `validate_path_security` uses string-prefix containment (`startswith`) for boundary checks. This allows paths that are **outside** the intended project directory but share its prefix string (e.g., `/tmp/potato_proj_demo_evil/...` vs `/tmp/potato_proj_demo`) to be accepted. ## Details ### Affected source location (root cause) **File:** `potato/server_utils/config_module.py` **Snippet (lines 370–373):** ```python real_path = os.path.realpath(normalized_path) real_base = os.path.realpath(base_dir) if not real_path.startswith(real_base): raise ConfigSecurityError(...) ``` **Snippet (lines 384–389):** ```python real_path = os.path.realpath(normalized_path) check_dir = project_dir if project_dir else base_dir real_check_dir = os.path.realpath(check_dir) if not real_path.startswith(real_check_dir): raise ConfigSecurityError(...) ``` `startswith()` is string-based, so `/tmp/potato_proj_demo_evil/...` passes when checked against `/tmp/potato_proj_demo`. ### Confirmed affected call sites **File:** `potato/server_utils/config_module.py` 1) `validate_file_paths` task_dir branch (line 2113) ```python validated_task_dir = validate_path_security(task_dir, project_dir) ``` 2) `validate_file_paths` data_files branch (line 2151) ```python validated_path = validate_path_security(file_path, base_dir, project_dir) ``` 3) `validate_training_config` training.data_file branch (line 2286) ```python validated_path = validate_path_security(data_file, base_dir, project_dir) ``` ## PoC ```python from potato.server_utils.config_module import validate_path_security base = '/tmp/potato_proj_demo' vuln = '/tmp/potato_proj_demo_evil/file.txt' try: print('inside=', validate_path_security('/tmp/potato_proj_demo/file.txt', base, base)) except Exception as e: print('inside_error=', type(e).__name__, e) try: validate_path_security('/tmp/other_demo/file.txt', base, base) except Exception as e: print('baseline=', type(e).__name__, e) print('trigger=', validat