Impact
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.
Patches
- Istio 1.13.2 and above
- Istio 1.12.5 and above
- Istio 1.11.8 and above
Workarounds
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.
References
golang/go#51112
For more information
If you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com
howardjohn Analyst
Impact
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.
Patches
Workarounds
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.
References
golang/go#51112
For more information
If you have any questions or comments about this advisory, please email us at istio-security-vulnerability-reports@googlegroups.com