Cis Ocp V190 1.3.2

---
name: cis-ocp-v190-1.3.2
description: "Ensure that the --use-service-account-credentials argument is set to true (Manual)"
category: cis-openshift
version: "1.9.0"
author: cyberstrike-official
tags: [cis, openshift, kubernetes, redhat, controller-manager, service-account, credentials, rbac]
cis_id: "1.3.2"
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 1.3.2

## Profile Applicability

- **Level:** 1

## Description

Use individual service account credentials for each controller.

## Rationale

The controller manager creates a service account per controller in the `kube-system` namespace, generates a credential for it, and builds a dedicated API client with that service account credential for each controller loop to use. Setting the `--use-service-account-credentials` to true runs each control loop within the controller manager using a separate service account credential. When used in combination with RBAC, this ensures that the control loops run with the minimum permissions required to perform their intended tasks.

## Impact

Whatever authorizer is configured for the cluster, it must grant sufficient permissions to the service accounts to perform their intended tasks. When using the RBAC authorizer, those roles are created and bound to the appropriate service accounts in the `kube-system` namespace automatically with default roles and `rolebindings` that are auto-reconciled on startup.

If using other authorization methods (ABAC, Webhook, etc), the cluster deployer is responsible for granting appropriate permissions to the service accounts (the required permissions can be seen by inspecting the `controller-roles.yaml` and `controller-role-bindings.yaml` files for the RBAC roles.

## Audit Procedure

In OpenShift, `--use-service-account-credentials` is set to `true` by default for the Controller Manager. The bootstrap configuration and overrides are available here:

- [kube-controller-manager-pod](https://github.com/openshift/cluster-kube-controller-manager-operator/blob/release-4.5/bindata/bootkube/bootstrap-manifests/kube-controller-manager-pod.yaml)
- [bootstrap-config-overrides](https://github.com/openshift/cluster-kube-controller-manager-operator/blob/release-4.5/bindata/bootkube/config/bootstrap-config-overrides.yaml)

Run the following command on the master node:

```bash
oc get configmaps config -n openshift-kube-controller-manager -ojson | \
  jq -r '.data["config.yaml"]' | \
  jq -r '.extendedArguments["use-service-account-credentials"][]'
```

Verify that the `--use-service-account-credentials` argument is set to `true`.

## Remediation

None.

## Default Value

By default, in OpenShift 4 `--use-service-account-credentials` is set to `true`.

The OpenShift Controller Manager operator manages and updates the OpenShift Controller Manager. The Kubernetes Controller Manager operator manages and updates the Kubernetes Controller Manager deployed on top of OpenShift. This operator is configured via KubeControllerManager custom resource.

## References

1. https://docs.openshift.com/container-platform/latest/operators/operator-reference.html
2. https://github.com/openshift/cluster-kube-controller-manager-operator/tree/master
3. https://github.com/openshift/cluster-kube-controller-manager-operator/blob/release-4.5/bindata/bootkube/bootstrap-manifests/kube-controller-manager-pod.yaml
4. https://github.com/openshift/cluster-kube-controller-manager-operator/blob/release-4.5/bindata/bootkube/config/bootstrap-config-overrides.yaml
5. https://github.com/openshift/cluster-kube-controller-manager-operator/blob/release-4.5/bindata/v4.1.0/kube-controller-manager/kubeconfig-cm.yaml
6. https://github.com/openshift/cluster-openshift-controller-manager-operator/blob/release-4.5/bindata/v3.11.0/openshift-controller-manager/ds.yaml
7. https://github.com/openshift/cluster-openshift-controller-manager-operator/blob/release-4.5/bindata/v3.11.0/openshift-controller-manager/sa.yaml
8. https://github.com/openshift/cluster-openshift-controller-manager-operator/blob/release-4.5/bindata/v3.11.0/openshift-controller-manager/separate-sa-role.yaml
9. https://github.com/openshift/cluster-openshift-controller-manager-operator/blob/release-4.5/bindata/v3.11.0/openshift-controller-manager/separate-sa-rolebinding.yaml
10. https://kubernetes.io/docs/reference/command-line-tools-reference/kube-controller-manager/
11. https://kubernetes.io/docs/reference/access-authn-authz/service-accounts-admin/
12. https://github.com/kubernetes/kubernetes/blob/release-1.6/plugin/pkg/auth/authorizer/rbac/bootstrappolicy/testdata/controller-roles.yaml
13. https://github.com/kubernetes/kubernetes/blob/release-1.6/plugin/pkg/auth/authorizer/rbac/bootstrappolicy/testdata/controller-role-bindings.yaml
14. https://kubernetes.io/docs/reference/access-authn-authz/rbac/#controller-roles

## CIS Controls

| Controls Version | Control                  | IG 1 | IG 2 | IG 3 |
| ---------------- | ------------------------ | ---- | ---- | ---- |
| v8               | 5.2 Use Unique Passwords | X    | X    | X    |
| v7               | 4.4 Use Unique Passwords |      | X    | X    |

## MITRE ATT&CK Mappings

| Techniques / Sub-techniques | Tactics | Mitigations |
| --------------------------- | ------- | ----------- |
| T1078, T1548                | TA0001  | M1018       |

## Profile

**Level 1** (Manual)