python-utcp versions before 1.1.4 contain a server-side request forgery vulnerability in HttpCommunicationProtocol.call_tool that validates the initial tool URL but follows HTTP redirects without re-validating the target. Attackers controlling a tool endpoint can return a 302 redirect to internal services, allowing the UTCP client to reach cloud metadata endpoints or internal HTTP services and return their response bodies to the caller.
Weakness
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
Related Attack Patterns
References
- https://github.com/universal-tool-calling-protocol/python-utcp/security/advisories/GHSA-9qhg-99ww-9mqc
- https://www.vulncheck.com/advisories/python-utcp-before-1.1.4-ssrf-via-unvalidated-http-redirects
- https://github.com/universal-tool-calling-protocol/python-utcp/security/advisories/GHSA-9qhg-99ww-9mqc