cis-ocp-v160-1-2-17

name	cis-ocp-v160-1.2.17
description	Ensure that the --insecure-port argument is set to 0 (Manual)
category	cis-openshift
version	1.6.0
author	cyberstrike-official
tags	["cis","openshift","kubernetes","redhat","control-plane","api-server","insecure-port"]
cis_id	1.2.17
cis_benchmark	CIS Red Hat OpenShift Container Platform Benchmark v1.6.0
tech_stack	["kubernetes","openshift","redhat"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

CIS Red Hat OpenShift Container Platform Benchmark v1.6.0 - Control 1.2.17

Profile Applicability

• Level: 1

Description

Do not bind to insecure port.

Rationale

Setting up the apiserver to serve on an insecure port would allow unauthenticated and unencrypted access to your master node. This would allow attackers who could access this port, to easily take control of the cluster.

Impact

All components that use the API must connect via the secured port, authenticate themselves, and be authorized to use the API.

This includes:

• kube-controller-manager
• kube-proxy
• kube-scheduler
• kubelets

Audit Procedure

The openshift-kube-apiserver is served over HTTPS with authentication and authorization; the secure API endpoint is bound to 0.0.0.0:6443 by default. By default the insecure-port argument is set to 0. Note that the openshift-apiserver is not running in the host network namespace. The port is not exposed on the node, but only through the pod network.

Run the following command:

oc -n openshift-kube-apiserver get endpoints -o jsonpath='{.items[*].subsets[*].ports[*].port}'

Verify the return value is 6443.

Remediation

None.

Default Value

By default, the openshift-kube-server is served over HTTPS with authentication and authorization; the secure API endpoint is bound to 0.0.0.0:6443 and the insecure-port has been removed in Kubernetes 1.20+.

References

1. https://github.com/openshift/cluster-kube-apiserver-operator/blob/release-4.6/bindata/v4.1.0/config/defaultconfig.yaml#L102-L103
2. https://github.com/openshift/cluster-kube-apiserver-operator/blob/release-4.5/bindata/v4.1.0/config/defaultconfig.yaml#L103-L105
3. https://github.com/openshift/cluster-kube-apiserver-operator/blob/release-4.5/bindata/v4.1.0/kube-apiserver/pod.yaml#L155-L157