Cis K8S V1120 4.1.10

CIS Kubernetes Benchmark v1.12.0 - Control 4.1.10

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 Procedure

Step 1: Set the kubelet config yaml variable

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

Step 2: Verify file ownership

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/

CIS Controls

Profile Applicability

• Level 1 - Worker Node

Assessment Status

Automated