The OpenID Connect server implementation for MITREid Connect through 1.3.3 contains a Server Side Request Forgery (SSRF) vulnerability. The vulnerability arises due to unsafe usage of the logo_uri parameter in the Dynamic Client Registration request. An unauthenticated attacker can make a HTTP request from the vulnerable server to any address in the internal network and obtain its response (which might, for example, have a JavaScript payload for resultant XSS). The issue can be exploited to bypass network boundaries, obtain sensitive data, or attack other hosts in the internal network.