The instructions for rule ocp4-etcd-unique-ca are not accurate.
For 417 and higher versions, the instruction doesn’t work. 
% oc get rule ocp4-etcd-unique-ca -o=jsonpath={.instructions}
Run the following command:
oc debug node/$NODE -- diff /host/etc/kubernetes/static-pod-resources/etcd-certs/configmaps/etcd-serving-ca/ca-bundle.crt /host/etc/kubernetes/static-pod-resources/kube-apiserver-certs/configmaps/client-ca/ca-bundle.crt
where $NODE is a master node. If you don't see diff output
the differences, you might have a compromise and should isolate the cluster.
OpenShift will use separate PKIs by default.
Is it the case that The etcd CA certificate is not unique?%
 
% oc debug node/xiyuan-417-23a-ljr2n-master-0  -- diff /host/etc/kubernetes/static-pod-resources/etcd-certs/configmaps/etcd-serving-ca/ca-bundle.crt /host/etc/kubernetes/static-pod-resources/kube-apiserver-certs/configmaps/client-ca/ca-bundle.crt
Temporary namespace openshift-debug-4kr8v is created for debugging node...
Starting pod/xiyuan-417-23a-ljr2n-master-0-debug-jprt4 ...
To use host binaries, run `chroot /host`
diff: /host/etc/kubernetes/static-pod-resources/etcd-certs/configmaps/etcd-serving-ca/ca-bundle.crt: No such file or directory
Removing debug pod ...
Temporary namespace openshift-debug-4kr8v was removed.
error: non-zero exit code from debug container    

4.17.0-0.nightly-2024-09-22-162519 + compliance-operator.v1.6.0    

Always    

    1.   Install  compliance-operator.v1.6.0
    2.   Get the instructions for rule ocp4-etcd-unique-ca. And check whether the command in the instruction works or not.
% oc get rule ocp4-etcd-unique-ca -o=jsonpath={.instructions}     

The command in the instructions will return error.     

The command in the instructions should not return error.