Command execution in python-utcp allows attackers to achieve remote code execution when fetching a remote Manual from a malicious endpoint

Vulnerability Description

The vulnerability arises when a client fetches a tools’ JSON specification, known as a Manual, from a remote Manual Endpoint. While a provider may initially serve a benign manual (e.g., one defining an HTTP tool call), earning the clients’ trust, a malicious provider can later change the manual to exploit the client.

References

• https://research.jfrog.com/vulnerabilities/python-utcp-untrusted-manual-command-execution-jfsa-2025-001648329/
• https://github.com/universal-tool-calling-protocol/python-utcp/commit/2dc9c02df72cad3770c934959325ec344b441444