The /openai/models endpoint in open-webui/open-webui version 0.3.8 is vulnerable to Server-Side Request Forgery (SSRF). An attacker can change the OpenAI URL to any URL without checks, causing the endpoint to send a request to the specified URL and return the output. This vulnerability allows the attacker to access internal services and potentially gain command execution by accessing instance secrets.
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.