Attack Chain

1. The attacker identifies an MCP-Docusaurus instance running a vulnerable version (<= 404bc028e15ec304c9a045528560f4b5f27a17e0).
2. The attacker crafts a malicious HTTP request targeting the update_document, continue_document, delete_document, or get_content functions in app/routes/document.py.
3. The crafted request includes a modified DOCS_DIR/path argument containing path traversal sequences (e.g., ../, ../../).
4. The MCP-Docusaurus application processes the malicious request without proper validation of the path argument.
5. The application constructs a file path using the attacker-controlled path argument, resulting in access to files outside the intended DOCS_DIR directory.
6. The attacker successfully reads, modifies, or deletes arbitrary files on the server, depending on the function targeted and server permissions.
7. The attacker may escalate their access by retrieving sensitive configuration files containing credentials.
8. The attacker leverages compromised credentials to gain further access to the system or network.

Impact

Successful exploitation of this path traversal vulnerability allows attackers to read sensitive files, potentially including configuration files, source code, and user data. Depending on the permissions of the application, attackers may also be able to modify or delete files, leading to data corruption or denial of service. Given the public availability of the exploit, organizations using vulnerable versions of MCP-Docusaurus are at high risk of compromise. The lack of vendor response further exacerbates the risk.

Recommendation

• Monitor web server logs for suspicious requests containing path traversal sequences (../, ../../) in the URI, specifically targeting app/routes/document.py (see example Sigma rule below).
• Implement input validation and sanitization for the DOCS_DIR/path argument in the update_document, continue_document, delete_document, and get_content functions.
• Since specific version information is unavailable, prioritize upgrading to the latest version of MCP-Docusaurus as soon as a patch is released.
• Audit access control configurations to limit the application’s access to only necessary files and directories.