| name | cis-ocp-v160-1.3.2 |
| description | Ensure that the --use-service-account-credentials argument is set to true (Manual) |
| category | cis-openshift |
| version | 1.6.0 |
| 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 v1.6.0 |
| tech_stack | ["kubernetes","openshift","redhat"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
CIS Red Hat OpenShift Container Platform Benchmark v1.6.0 - Control 1.3.2
Profile Applicability
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
- bootstrap-config-overrides
Run the following command on the master node:
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.
