C-0146 - Ensure that the Controller Manager --use-service-account-credentials argument is set to true
Framework
cis-v1.23-t1.0.1
Severity
Medium
Description of the the issue
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.
Related resources
Pod
What does this control test
Use individual service account credentials for each controller.
How to check it manually
Run the following command on the Control Plane node:
ps -ef | grep kube-controller-manager
Verify that the --use-service-account-credentials
argument is set to true
.
Remediation
Edit the Controller Manager pod specification file /etc/kubernetes/manifests/kube-controller-manager.yaml
on the Control Plane node to set the below parameter.
--use-service-account-credentials=true
Impact Statement
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.
Default Value
By default, --use-service-account-credentials
is set to false.
Example
No example
Updated 3 days ago