Cis Ocp V190 1.4.1

---
name: cis-ocp-v190-1.4.1
description: "Ensure that the healthz endpoints for the scheduler are protected by RBAC (Manual)"
category: cis-openshift
version: "1.9.0"
author: cyberstrike-official
tags: [cis, openshift, kubernetes, redhat, scheduler, rbac, profiling, healthz]
cis_id: "1.4.1"
cis_benchmark: "CIS Red Hat OpenShift Container Platform Benchmark v1.9.0"
tech_stack: [kubernetes, openshift, redhat]
cwe_ids: []
chains_with: []
prerequisites: []
severity_boost: {}
---

# CIS Red Hat OpenShift Container Platform Benchmark v1.9.0 - Control 1.4.1

## Profile Applicability

- **Level:** 1

## Description

Disable profiling, if not needed.

## Rationale

Profiling allows for the identification of specific performance bottlenecks. It generates a significant amount of program data that could potentially be exploited to uncover system and program details. If you are not experiencing any bottlenecks and do not need the profiler for troubleshooting purposes, it is recommended to turn it off to reduce the potential attack surface.

## Impact

Profiling information would not be available.

## Audit Procedure

In OpenShift 4, The Kubernetes Scheduler operator manages and updates the Kubernetes Scheduler deployed on top of OpenShift. By default, the operator exposes metrics via metrics service. The metrics are collected from the Kubernetes Scheduler operator. Profiling data is sent to `healthzPort`, the port of the localhost `healthz` endpoint. Changing this value may disrupt components that monitor the kubelet health. The default `healthz port` value is `10251`, and the `healthz bindAddress` is `127.0.0.1`.

To ensure the collected data is not exploited, profiling endpoints are secured via RBAC (see cluster-debugger role). By default, the profiling endpoints are accessible only by users bound to `cluster-admin` or `cluster-debugger` role. Profiling can not be disabled.

To verify the configuration, run the following command:

Run the following command to check the `livenessProbe` configuration:

```bash
oc -n openshift-kube-scheduler get cm kube-scheduler-pod -o json | jq -r '.data."pod.yaml"' | jq '.spec.containers[].livenessProbe'
```

Verify the output path is set to `healthz`.

Run the following command to check the `readinessProbe` configuration:

```bash
oc -n openshift-kube-scheduler get cm kube-scheduler-pod -o json | jq -r '.data."pod.yaml"' | jq '.spec.containers[].readinessProbe'
```

Verify the output path is set to `healthz`.

Verify endpoints exist for the scheduler:

```bash
oc -n openshift-kube-scheduler describe endpoints
```

Validate that RBAC is enabled and protects controller endpoints. First, switch to the `openshift-kube-scheduler`:

```bash
oc project openshift-kube-scheduler
```

Next, get the schedule pod name and port:

```bash
export POD=$(oc get pods -l app=openshift-kube-scheduler -o jsonpath='{.items[0].metadata.name}')
export PORT=$(oc get pod $POD -o jsonpath='{.spec.containers[0].livenessProbe.httpGet.port}')
```

Attempt to make an insecure GET request to the metrics endpoint:

```bash
oc rsh $POD curl https://localhost:$PORT/metrics -k
```

Verify that an HTTP `403` is returned.

Create a test service account:

```bash
oc create sa permission-test-sa
```

Generate a service account token and attempt to access the metrics endpoint:

```bash
export SA_TOKEN=$(oc create token permission-test-sa)
oc rsh $POD curl http://localhost:$PORT/metrics -H "Authorization: Bearer $SA_TOKEN" -k
```

Verify that an HTTP `403` is returned.

Login as a cluster administrator and attempt to access the metrics endpoint:

```bash
CLUSTER_ADMIN_TOKEN=$(oc whoami -t)
oc rsh $POD curl https://localhost:$PORT/metrics -H "Authorization: Bearer $CLUSTER_ADMIN_TOKEN" -k
```

Verify metrics output is returned. Unset environment variables used in the test and delete the test service account:

```bash
unset CLUSTER_ADMIN_TOKEN POD PORT SA_TOKEN
oc delete sa permission-test-sa
```

## Remediation

None.

## Default Value

By default, profiling is enabled and protected by RBAC.

## References

1. https://github.com/openshift/cluster-kube-scheduler-operator
2. https://github.com/openshift/cluster-kube-scheduler-operator/blob/release-4.5/bindata/v4.1.0/kube-scheduler/svc.yaml
3. https://github.com/openshift/cluster-kube-scheduler-operator/blob/release-4.5/bindata/v4.1.0/kube-scheduler/pod.yaml
4. https://github.com/openshift/cluster-kube-scheduler-operator/blob/release-4.5/bindata/v4.1.0/kube-scheduler/pod.yaml#L32-L37
5. https://kubernetes.io/docs/reference/command-line-tools-reference/kube-scheduler/
6. https://github.com/kubernetes/community/blob/master/contributors/devel/sig-scalability/profiling.md

## CIS Controls

| Controls Version | Control                                               | IG 1 | IG 2 | IG 3 |
| ---------------- | ----------------------------------------------------- | ---- | ---- | ---- |
| v8               | 6.8 Define and Maintain Role-Based Access Control     |      |      | X    |
| v7               | 14.6 Protect Information through Access Control Lists | X    | X    | X    |

## MITRE ATT&CK Mappings

| Techniques / Sub-techniques | Tactics | Mitigations |
| --------------------------- | ------- | ----------- |
| T1609                       | TA0002  | M1035       |

## Profile

**Level 1** (Manual)