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 web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.