An unauthenticated arbitrary file write vulnerability in 03-lovepreetSingh MCP allows remote attackers to overwrite critical system files and potentially achieve remote code execution.

This is a path traversal vulnerability (CWE-22) located in the create_file function within app/api/mcp/route.ts. The application fails to sanitize the filePath argument, allowing an unauthenticated remote attacker to escape the intended upload directory and write files to arbitrary locations on the host filesystem.

The ability for an unauthenticated attacker to write arbitrary files to the server poses a critical risk to business operations. By overwriting configuration files, startup scripts, or application source code, an attacker can gain full control over the affected system, resulting in total data compromise, service disruption, and potential lateral movement within the network. While the provided CVSS score is 7.3, the potential for remote code execution via file overwrite indicates a higher severity in practice.

Immediate Action: As no official patch is currently available, users should immediately restrict access to the MCP interface or disable the create_file tool entirely until the vendor releases a secure version that implements proper path canonicalization and input validation.

Proactive Monitoring: Monitor server filesystem integrity and review access logs for requests containing path traversal sequences, such as double dots (../) or absolute path indicators, directed at the /api/mcp/route.ts endpoint.

Compensating Controls: Deploy a Web Application Firewall (WAF) with rules configured to block requests containing directory traversal patterns in the JSON payload of the create_file tool.

Public Exploit Available: Yes, a published proof-of-concept exists as documented in the GitHub issue report provided by the researcher.

Given the lack of a vendor-provided patch and the availability of a functional proof-of-concept, this vulnerability represents an immediate and severe risk. Organizations utilizing 03-lovepreetSingh MCP must prioritize the isolation of this service from untrusted networks and implement strict access controls to prevent unauthorized interaction with the vulnerable create_file tool.