Information
Validate service account before validating token.
Rationale:
By default, the apiserver only verifies that the authentication token is valid. However, it does not validate that the service account token mentioned in the request is actually present in etcd. This allows using a service account token even after the corresponding service account is deleted. This is an example of time of check to time of use security issue.
Solution
Edit the deployment specs and set '--service-account-lookup=true'.
kubectl edit deployments federation-apiserver-deployment --namespace=federation-system
Impact:
None