C-0188 - Minimize access to create pods

Framework

ClusterScan, cis-aks-t1.2.0, cis-eks-t1.2.0, cis-v1.23-t1.0.1

Severity

Medium

Description of the the issue

The ability to create pods in a cluster opens up possibilities for privilege escalation and should be restricted, where possible.

Related resources

ClusterRole, ClusterRoleBinding, Role, RoleBinding

What does this control test

Check which subjects have RBAC permissions to create pods.

How to check it manually

Review the users who have create access to pod objects in the Kubernetes API.

Remediation

Where possible, remove create access to pod objects in the cluster.

Impact Statement

Care should be taken not to remove access to pods to system components which require this for their operation

Default Value

By default in a kubeadm cluster the following list of principals have create privileges on pod objects CLUSTERROLEBINDING SUBJECT TYPE SA-NAMESPACEcluster-admin system:masters Group system:controller:clusterrole-aggregation-controller clusterrole-aggregation-controller ServiceAccount kube-systemsystem:controller:daemon-set-controller daemon-set-controller ServiceAccount kube-systemsystem:controller:job-controller job-controller ServiceAccount kube-systemsystem:controller:persistent-volume-binder persistent-volume-binder ServiceAccount kube-systemsystem:controller:replicaset-controller replicaset-controller ServiceAccount kube-systemsystem:controller:replication-controller replication-controller ServiceAccount kube-systemsystem:controller:statefulset-controller statefulset-controller ServiceAccount kube-system

Example

No example