$ oc get clusterversion
NAME      VERSION   AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.11.20   True        False         43h     Cluster version is 4.11.20

$ oc get clusterrolebinding system:controller:ttl-controller -o yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  creationTimestamp: "2023-01-11T13:09:19Z"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:controller:ttl-controller
  resourceVersion: "204"
  uid: 74536183-0c18-44eb-9ce2-afcd85542580
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:controller:ttl-controller
subjects:
- kind: ServiceAccount
  name: ttl-controller
  namespace: kube-system

$ oc get sa ttl-controller -n kube-system
Error from server (NotFound): serviceaccounts "ttl-controller" not found

The serviceAccount ttl-controller does not exist. Neither in kube-system nor in any other namespace.

It's therefore not clear what this ClusterRoleBinding does, what use-case it does fulfill and why it references non existing serviceAccount.

From Security point of view, it's recommended to remove non serviceAccounts from ClusterRoleBindings as a potential attacker could abuse the current state by creating the necessary serviceAccount and gain undesired permissions.

OpenShift Container Platform 4 (all version from what we have found)

Always

1. Install OpenShift Container Platform 4
2. Run oc get clusterrolebinding system:controller:ttl-controller -o yaml

$ oc get clusterrolebinding system:controller:ttl-controller -o yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  creationTimestamp: "2023-01-11T13:09:19Z"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:controller:ttl-controller
  resourceVersion: "204"
  uid: 74536183-0c18-44eb-9ce2-afcd85542580
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:controller:ttl-controller
subjects:
- kind: ServiceAccount
  name: ttl-controller
  namespace: kube-system

$ oc get sa ttl-controller -n kube-system
Error from server (NotFound): serviceaccounts "ttl-controller" not found

The serviceAccount called ttl-controller to exist or otherwise the ClusterRoleBinding to be removed.

Finding related to a Security review done on the OpenShift Container Platform 4 - Platform