3.2.1 Ensure that the Anonymous Auth is Not Enabled Draft

Information

Disable anonymous requests to the Kubelet server.

When enabled, requests that are not rejected by other configured authentication methods are treated as anonymous requests. These requests are then served by the Kubelet server. You should rely on authentication to authorize access and disallow anonymous requests.

Solution

Remediation Method 1:

If configuring via the Kubelet config file, you first need to locate the file.

To do this, SSH to each node and execute the following command to find the kubelet process:

ps -ef | grep kubelet

The output of the above command provides details of the active kubelet process, from which we can see the location of the configuration file provided to the kubelet service with the --config argument. The file can be viewed with a command such as more or less like so:

sudo less /path/to/kubelet-config.json

Disable Anonymous Authentication by setting the following parameter:

"authentication": { "anonymous": { "enabled": false } }

Remediation Method 2:

If using executable arguments, edit the kubelet service file on each worker node and ensure the below parameters are part of the KUBELET_ARGS variable string.

For systems using systemd such as the Amazon EKS Optimised Amazon Linux or Bottlerocket AMIs, then this file can be found at /etc/systemd/system/kubelet.service.d/10-kubelet-args.conf Otherwise, you may need to look up documentation for your chosen operating system to determine which service manager is configured:

--anonymous-auth=false

For Both Remediation Steps:

Based on your system, restart the kubelet service and check the service status.

The following example is for operating systems using systemd such as the Amazon EKS Optimised Amazon Linux or Bottlerocket AMIs, and invokes the systemctl command. If systemctl is not available then you will need to look up documentation for your chosen operating system to determine which service manager is configured:

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

Impact:

Anonymous requests will be rejected.

See Also

https://workbench.cisecurity.org/benchmarks/16093