cis-ocp-v160-1-3-5

name	cis-ocp-v160-1.3.5
description	Ensure that the --bind-address argument is set to 127.0.0.1 (Manual)
category	cis-openshift
version	1.6.0
author	cyberstrike-official
tags	["cis","openshift","kubernetes","redhat","controller-manager","bind-address","network-security"]
cis_id	1.3.5
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 1.3.5

Profile Applicability

• Level: 1

Description

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

Rationale

The Controller Manager API service which runs on port 10257/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.

Impact

None.

Audit Procedure

The bind-address argument is not used. The secure-port argument is set to 10257. The insecure-port argument is set to 0.

Use the following command to check the secure port configuration:

oc get configmaps config -n openshift-kube-controller-manager -ojson | jq -r '.data["config.yaml"]' | jq '.extendedArguments["secure-port"][]'

Verify the returned value is 10257.

Ensure the metrics endpoint is protected from unauthorized access:

export POD=$(oc get pods -n openshift-kube-controller-manager -l app=kube-controller-manager -o jsonpath='{.items[0].metadata.name}')
oc rsh -n openshift-kube-controller-manager -c kube-controller-manager $POD curl https://localhost:10257/metrics -k

Verify an HTTP 403 response is returned and unset environment variables:

unset POD

Remediation

None.

Default Value

By default, the --bind-address argument is not present, the secure-port argument is set to 10257 and the port argument is set to 0.

References

1. https://docs.openshift.com/container-platform/4.5/operators/operator-reference.html#cluster-openshift-controller-manager-operator_red-hat-operators
2. https://docs.openshift.com/container-platform/4.5/operators/operator-reference.html#kube-controller-manager-operator_red-hat-operators