cyberstrikeus 5.1.4 Minimize access to create pods (Manual)
Profile Applicability
- Level 1 - Master Node
Description
The ability to create pods in a namespace can provide a number of opportunities for privilege escalation, such as assigning privileged service accounts to these pods or mounting hostPaths with access to sensitive data (unless Pod Security Policies are implemented to restrict this access).
As such, access to create new pods should be restricted to the smallest possible group of users.
Rationale
The ability to create pods in a cluster opens up possibilities for privilege escalation and should be restricted, where possible.
Impact
Care should be taken not to remove access to pods to system components which require this for their operation.
Audit
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.
Default Value
By default in a kubeadm cluster the following list of principals have create privileges on pod objects:
| CLUSTERROLEBINDING | SUBJECT |
|---|---|
| cluster-admin (Group) | system:masters |
| system:controller:clusterrole-aggregation-controller (ServiceAccount kube-system) | clusterrole-aggregation-controller |
| system:controller:daemon-set-controller (ServiceAccount kube-system) | daemon-set-controller |
| system:controller:job-controller (ServiceAccount kube-system) | job-controller |
| system:controller:persistent-volume-binder (ServiceAccount kube-system) | persistent-volume-binder |
| system:controller:replicaset-controller (ServiceAccount kube-system) | replicaset-controller |
| system:controller:replication-controller (ServiceAccount kube-system) | replication-controller |
| system:controller:statefulset-controller (ServiceAccount kube-system) | statefulset-controller |
References
None specified.