Istio is an open platform-independent service mesh that provides traffic management, policy enforcement, and telemetry collection. Prior to versions 1.15.2, 1.14.5, and 1.13.9, the Istio control plane, istiod, is vulnerable to a request processing error, allowing a malicious attacker that sends a specially crafted or oversized message which results in the control plane crashing when the Kubernetes validating or mutating webhook service 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 topologies, this port is exposed over the public internet. Versions 1.15.2, 1.14.5, and 1.13.9 contain patches for this issue. There are no effective workarounds, beyond upgrading. This bug is due to an error in regexp.Compile in Go.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Istio | Istio | * | 1.13.9 (excluding) |
| Istio | Istio | 1.14.0 (including) | 1.14.5 (excluding) |
| Istio | Istio | 1.15.0 (including) | 1.15.2 (excluding) |
| Red Hat OpenShift Service Mesh 2.3 for RHEL 8 | RedHat | openshift-service-mesh/istio-cni-rhel8:2.3.1-9 | * |
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.