KubernetesOverview
Kubernetes Roles and ClusterRoles provide access to resources based on sets of objects and actions that can be taken on those objects. It is possible to set either of these to be the wildcard "*" which matches all items.
Use of wildcards is not optimal from a security perspective as it may allow for inadvertent access to be granted when new resources are added to the Kubernetes API either as CRDs or in later versions of the product.
Rationale
The principle of least privilege recommends that users are provided only the access required for their role and nothing more. The use of wildcard rights grants is likely to provide excessive rights to the Kubernetes API.
Audit
Retrieve the roles defined across each namespaces in the cluster and review for wildcards:
kubectl get roles --all-namespaces -o yaml
Retrieve the cluster roles defined in the cluster and review for wildcards
kubectl get clusterroles -o yaml
Remediation guidance
Where possible, replace any use of wildcards in ClusterRoles and Roles with specific objects or actions.
References
Multiple Remediation Paths
SERVICE-WIDE (RECOMMENDED when many resources are affected): Apply organization/tenant-level guardrails and baseline policies for the entire platform.
ASSET-LEVEL: Fix only the affected resources identified by this control.
PREVENTIVE: Add preventive policy checks to CI/CD and periodic posture scans.
References for Service-Wide Patterns
- Platform policy/governance and preventive control patterns should be applied tenant-wide where supported.
Query logic
These are the stored checks tied to this control.
Kubernetes Roles with wildcard rules
Connectors
Covered asset types
Expected check: eq []
{
roles (where: {rules_SOME: {AND: [{verbs_INCLUDES: "*"}, {resources_INCLUDES: "*"}, {OR: [{apiGroup_INCLUDES: ""}, {apiGroup_INCLUDES: "*"}]}]}}){
...AssetFragment
}
}Kubernetes ClusterRoles with wildcard rules
Connectors
Covered asset types
Expected check: eq []
{
clusterRoles (where: {rules_SOME: {AND: [{verbs_INCLUDES: "*"}, {resources_INCLUDES: "*"}, {OR: [{apiGroup_INCLUDES: ""}, {apiGroup_INCLUDES: "*"}]}]}}){
...AssetFragment
}
}
