Cis Ocp V160 5.1.2

CIS Red Hat OpenShift Container Platform Benchmark v1.6.0 - Control 5.1.2

Profile Applicability

• Level: 1

Description

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.

Audit Procedure

Review the users who have get, list or watch access to secrets objects in the Kubernetes API.

Executing the command below will return a list of users and groups who are allowed to get secrets:

oc adm policy who-can get secrets

The following command returns the users and groups who are allowed to list secrets:

oc adm policy who-can list secrets

The following command returns the users and groups who are allowed to watch secrets:

oc adm policy who-can watch secrets

Remediation

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

References

1. https://kubernetes.io/docs/concepts/configuration/secret/#using-secrets

CIS Controls

MITRE ATT&CK Mappings

Profile

Level 1 (Manual)