Information
The Kubernetes API stores secrets, which may be service account tokens for the Kubernetes API or credentials used by workloads in the cluster. Access to these secrets should be restricted to the smallest possible group of users to reduce the risk of privilege escalation.
Rationale:
Inappropriate access to secrets stored within the Kubernetes cluster can allow for an attacker to gain additional access to the Kubernetes cluster or external resources whose credentials are stored as secrets.
Impact:
Care should be taken not to remove access to secrets to system components which require this for their operation
NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.
Solution
Where possible, remove get, list and watch access to secret objects in the cluster.
Default Value:
By default in a OpenShift cluster the following list of principals have get privileges on secret objects
for i in $(oc get clusterroles -o jsonpath='{.items[*].metadata.name}'); do oc describe clusterrole ${i}; done
# The following default cluster roles have get privileges on secret objects
admin
cloud-credential-operator-role
cluster-admin
cluster-image-registry-operator
cluster-monitoring-operator
cluster-node-tuning-operator
edit
kube-state-metrics
machine-config-controller
marketplace-operator
openshift-ingress-operator
prometheus-operator
registry-admin
registry-editor
system:aggregate-to-edit
system:controller:expand-controller
system:controller:generic-garbage-collector
system:controller:namespace-controller
system:controller:operator-lifecycle-manager
system:controller:persistent-volume-binder
system:kube-controller-manager
system:master
system:node
system:openshift:controller:build-controller
system:openshift:controller:cluster-quota-reconciliation-controller
system:openshift:controller:ingress-to-route-controller
system:openshift:controller:service-ca
system:openshift:controller:service-serving-cert-controller
system:openshift:controller:serviceaccount-pull-secrets-controller
system:openshift:controller:template-service-broker