A flaw was found in the OpenShift Router. When a Route has `insecureEdgeTerminationPolicy` set to Allow, the HTTP frontend does not remove `X-SSL-Client-*` headers from incoming requests. This allows an unauthenticated attacker to send plain HTTP requests with crafted `X-SSL-Client-*` headers. As a result, backends relying on these headers for mutual TLS (Transport Layer Security) authentication can be bypassed, enabling the attacker to impersonate client certificate identities.
Credits
This issue was discovered by Ricardo Pchevuzinske Katz (Red Hat).