1.3.7 - Ensure that the --bind-address argument is set to 127.0.0.1 (Automated)

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Profile applicability: Level 1 - Master Node

Do not bind the Controller Manager service to non-loopback insecure addresses.

The Controller Manager API service which runs on port 10252/TCP by default is used for health and metrics information and is available without authentication or encryption. As such it should only be bound to a localhost interface, to minimize the cluster's attack surface.

Note

By default, the --bind-address parameter is set to 0.0.0.0.

Audit

Run the following command on the Control Plane node:

ps -ef | grep kube-controller-manager

Verify that the --bind-address argument is set to 127.0.0.1

Remediation

Edit the Controller Manager pod specification file /etc/kubernetes/manifests/kube-controller-manager.yaml on the Control Plane node and ensure the correct value for the --bind-address parameter.

Note

Although the current Kubernetes documentation site says that --address is deprecated in favour of --bind-address Kubeadm 1.11 still makes use of --address.