Istio is an open platform to connect, manage, and secure microservices. In affected versions the Istio control plane, istiod, is vulnerable to a request processing error, allowing a malicious attacker that sends a specially crafted message which results in the control plane crashing when the validating webhook for a cluster is exposed publicly. This endpoint is served over TLS port 15017, but does not require any authentication from the attacker. For simple installations, Istiod is typically only reachable from within the cluster, limiting the blast radius. However, for some deployments, especially [external istiod](https://istio.io/latest/docs/setup/install/external-controlplane/) topologies, this port is exposed over the public internet. This issue has been patched in versions 1.13.2, 1.12.5 and 1.11.8. Users are advised to upgrade. Users unable to upgrade should disable access to a validating webhook that is exposed to the public internet or restrict the set of IP addresses that can query it to a set of known, trusted entities.

envoy: Null pointer dereference when using JWT filter safe_regex match envoy: Use-after-free when response filters increase response data envoy: Use-after-free when tunneling TCP over HTTP envoy: Incorrect configuration handling allows mTLS session re-use without re-validation envoy: Incorrect handling of internal redirects to routes with a direct response entry envoy: Stack exhaustion when a cluster is deleted via Cluster Discovery Service istio: unauthenticated control plane denial of service attack istio: Unauthenticated control plane denial of service attack due to stack exhaustion

Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Red Hat OpenShift ausnutzen, um einen Denial-of-Service-Zustand zu verursachen und Sicherheitsmaßnahmen zu umgehen.