A half-blind Server Side Request Forgery (SSRF) vulnerability exists in kube-controller-manager when using the in-tree Portworx StorageClass. This vulnerability allows authorized users to leak arbitrary information from unprotected endpoints in the control plane’s host network (including link-local or loopback services).
The Kubernetes kube-controller-manager in versions v1.0-1.14, versions prior to v1.15.12, v1.16.9, v1.17.5, and version v1.18.0 are vulnerable to a Server Side Request Forgery (SSRF) that allows certain authorized users to leak up to 500 bytes of arbitrary information from unprotected endpoints within the master's host network (such as link-local or loopback services).