A security issue was discovered in Kubernetes where actors that control the responses of MutatingWebhookConfiguration or ValidatingWebhookConfiguration requests are able to redirect kube-apiserver requests to private networks of the apiserver. If that user can view kube-apiserver logs when the log level is set to 10, they can view the redirected responses and headers in the logs.
The product receives a request, message, or directive from an upstream component, but the product does not sufficiently preserve the original source of the request before forwarding the request to an external actor that is outside of the product's control sphere. This causes the product to appear to be the source of the request, leading it to act as a proxy or other intermediary between the upstream component and the external actor.
The product uses an externally controlled name or reference that resolves to a resource that is outside of the intended control sphere.
| Link | Tags |
|---|---|
| https://groups.google.com/g/kubernetes-security-announce/c/RV2IhwcrQsY | mitigation mailing list |
| https://github.com/kubernetes/kubernetes/issues/104720 | mitigation third party advisory |
| https://security.netapp.com/advisory/ntap-20211014-0002/ | third party advisory |