Details
Disable the read-only port.
Rationale:
The Kubelet process provides a read-only API in addition to the main Kubelet API. Unauthenticated access is provided to this read-only API which could possibly retrieve potentially sensitive information about the cluster.
Impact:
Removal of the read-only port will require that any service which made use of it will need to be re-configured to use the main Kubelet API.
Solution
If using a Kubelet config file, edit the file to set readOnlyPort to 0.
If using command line arguments, edit the kubelet service file /etc/systemd/system/kubelet.service.d/10-kubeadm.conf on each worker node and set the below parameter in KUBELET_SYSTEM_PODS_ARGS variable.
–read-only-port=0
Based on your system, restart the kubelet service. For example:
systemctl daemon-reload
systemctl restart kubelet.service
Default Value:
By default, –read-only-port is set to 10255/TCP. However, if a config file is specified by –config the default value for readOnlyPort is 0.
Supportive Information
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: Configuration Management.This control applies to the following type of system Unix.