An unauthenticated arbitrary file write vulnerability in BioinfoMCP allows remote attackers to overwrite system files, posing a significant risk to server integrity and operational stability.

The application fails to sanitize the filename parameter during multipart file uploads in the bioinfo_mcp_platform/app.py script, enabling path traversal. This allows an unauthenticated attacker to write files to arbitrary locations on the host filesystem by providing a crafted filename.

Successful exploitation grants an attacker the ability to overwrite critical system files or application configuration files, potentially leading to full system compromise or service disruption. While the CVSS score is 7.3, the high impact on file integrity and the potential for subsequent code execution make this a high-priority risk. Unauthorized file modification can lead to data loss, service downtime, and reputational damage for organizations relying on this platform.

Immediate Action: As no official patch is currently available, restrict access to the BioinfoMCP web interface to trusted users only via network-level controls such as VPNs or IP whitelisting.

Proactive Monitoring: Monitor server logs for POST requests to the /upload endpoint that contain suspicious file path characters, such as directory traversal sequences or absolute paths starting with a forward slash.

Compensating Controls: Deploy a Web Application Firewall (WAF) configured to inspect multipart/form-data payloads and block requests containing directory traversal sequences or non-standard characters in the filename field.

Public Exploit Available: Yes — a public proof-of-concept is documented in the researcher's GitHub issue report.

Given the availability of a public proof-of-concept and the lack of a vendor-supplied patch, immediate defensive action is required. Organizations should isolate the affected instance from the public internet and implement strict access controls until the developer provides a secure version that utilizes filename sanitization or server-side random file naming.