Cis Oke V150 3.2.4

3.2.4 Ensure that the --read-only-port argument is set to 0 (Automated)

Profile Applicability

• Level 1

Description

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.

Audit Procedure

If using a Kubelet configuration file, check that there is an entry for --read-only-port=0. First, SSH to the relevant node: Run the following command on each node to find the appropriate Kubelet service config file:

find / -name kubelet.service

The output of the above command should return the file and location /etc/systemd/system/kublet.service which is the location of the Kubelet service config file. Open the Kubelet service config file:

sudo more etc/systemd/system/kublet.service

Verify that the --read-only-port argument exists and is set to 0. If the --read-only-port argument is not present, check that there is a Kubelet config file specified by --config. Check that if there is a readOnlyPort entry in the file, it is set to 0.

Remediation

If modifying the Kubelet config file, edit the kubelet.service file /etc/sytemd/system/kubelet.service and set the below parameter

--read-only-port=0

For all remediations: Based on your system, restart the kubelet service and check status

systemctl daemon-reload
systemctl restart kubelet.service
systemctl status kubelet -l

Default Value

See the OKE documentation for the default value.

References

1. https://kubernetes.io/docs/admin/kubelet/

CIS Controls

MITRE ATT&CK Mappings

Profile: Level 1 - CIS Oracle Cloud Infrastructure Container Engine for Kubernetes (OKE) Benchmark v1.5.0