MindsDB: Path Traversal in /api/files Leading to Remote Code Execution

### Summary There is a path traversal vulnerability in Mindsdb's /api/files interface, which an authenticated attacker can exploit to achieve remote command execution. ### Details The vulnerability exists in the "Upload File" module, which corresponds to the API endpoint /api/files. The affected code is located at mindsdb/api/http/namespaces/file.py: ```python @ns_conf.route("/<name>") @ns_conf.param("name", "MindsDB's name for file") class File(Resource): @ns_conf.doc("put_file") @api_endpoint_metrics('PUT', '/files/file') def put(self, name: str): """add new file params in FormData: - file - original_file_name [optional] """ data = {} mindsdb_file_name = name existing_file_names = ca.file_controller.get_files_names() def on_field(field): name = field.field_name.decode() value = field.value.decode() data[name] = value file_object = None def on_file(file): nonlocal file_object data["file"] = file.file_name.decode() file_object = file.file_object temp_dir_path = tempfile.mkdtemp(prefix="mindsdb_file_") if request.headers["Content-Type"].startswith("multipart/form-data"): parser = multipart.create_form_parser( headers=request.headers, on_field=on_field, on_file=on_file, config={ "UPLOAD_DIR": temp_dir_path.encode(), # bytes required "UPLOAD_KEEP_FILENAME": True, "UPLOAD_KEEP_EXTENSIONS": True, "MAX_MEMORY_FILE_SIZE": 0, }, ) while True: chunk = request.stream.read(8192) if not chunk: break parser.write(chunk) parser.finalize() parser.close() if file_object is not None: if not file_object.closed: try: file_object.flush() except (AttributeError, ValueError, OSError): logger.debug("Failed to flush file_object before closing.", exc_info=True) file_object.close() file_object = None else: data = request.json ``` Since the multipart file upload does not perform security checks on the uploaded file path, an attacker can perform path traversal by using ../ sequences in the filename field. The file write operation occurs before calling clear_filename and save_file, meaning there is no filtering of filenames or file types, allowing arbitrary content to be written to any path on the server. ### PoC This vulnerability can be exploited to overwrite existing executable files, which retain their executable permissions after being overwritten. In addition to conventional file upload exploitation methods, we provide a way to achieve Remote Code Execution (RCE) by leveraging MindsDB's own functionality. The API endpoint /<handler_name>/install is used to install handlers, which internally calls install_dependencies to install dependencies via pip. This function executes pip using subprocess.Popen. Therefore, an attacker can: 1. Exploit the vulnerability to overwrite /venv/lib/python3.10/site-packages/pip/__init__.py with a malicious Python script. 2. Trigger the execution of the malicious script by calling /<handler_name>/install, which invokes pip. Exploit： ``` PUT /api/files/mm HTTP/1.1 Host: ip:47334 Content-Length: 579 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36 Accept: application/json, text/plain, */* Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryv9dZC0cAHLlHSHD9 Origin: http://ip:47334 Referer: http://ip:47334/fileUpload Accept-Encoding: gzip, deflate, br Accept-Language: z

CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity from

GitHub (reviewed advisory)

Weakness

CWE-22

Also known as

CVE-2026-27483, PYSEC-2026-2205

• github.com/mindsdb/mindsdb/security/advisories/GHSA-4894-xqv6-vrfq
• nvd.nist.gov/vuln/detail/CVE-2026-27483
• github.com/mindsdb/mindsdb/commit/87a44bdb2b97f963e18f10a068e1a1e2690505ef
• github.com/mindsdb/mindsdb
• github.com/mindsdb/mindsdb/releases/tag/v25.9.1.1