Cis K8S V1111 4.1.10

4.1.10 If the kubelet config.yaml configuration file is being used validate file ownership is set to root:root (Automated)

Profile Applicability

• Level 1 - Worker Node

Description

Ensure that if the kubelet refers to a configuration file with the --config argument, that file is owned by root:root.

Rationale

The kubelet reads various parameters, including security settings, from a config file specified by the --config argument. If this file is specified you should restrict its file permissions to maintain the integrity of the file. The file should be owned by root:root.

Impact

None

Audit

Automated AAC auditing has been modified to allow CIS-CAT to input a variable for the <PATH>/<FILENAME> of the kubelet config yaml file. Please set $kubelet_config_yaml=<PATH> based on the file location on your system for example:

export kubelet_config_yaml=/var/lib/kubelet/config.yaml

To perform the audit manually: Run the below command (based on the file location on your system) on the each worker node. For example,

stat -c %U:%G /var/lib/kubelet/config.yaml

Verify that the ownership is set to root:root.

Remediation

Run the following command (using the config file location identified in the Audit step)

chown root:root /etc/kubernetes/kubelet.conf

Default Value

By default, /var/lib/kubelet/config.yaml file as set up by kubeadm is owned by root:root.

References

1. https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/

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