4.2.4 Verify that the --read-only-port argument is set to 0

Information

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/kubernetes/kubelet.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.

See Also

https://workbench.cisecurity.org/files/3891

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, 800-53|CM-7, CSCv7|9.2

Plugin: Unix

Control ID: 61feb462795a07863065e04f4cb06b3c67513ec1f96966d27ed73541c75e45ee