Envoy Proxy Vulnerability - CVE-2023-27496

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0 1.25.3 1.24.4 1.23.6 and 1.22.9 the OAuth filter assumes that a state query param is present on any response that looks like an OAuth redirect response. Sending it a request with the URI path equivalent to the redirect path without the state parameter will lead to abnormal termination of Envoy process. Versions 1.26.0 1.25.3 1.24.4 1.23.6 and 1.22.9 contain a patch. The issue can also be mitigated by locking down OAuth traffic disabling the filter or by filtering traffic before it reaches the OAuth filter (e.g. via a lua script).