kube-bench/cfg/gke-1.0/policies.yaml

---
controls:
version: "gke-1.0"
id: 5
text: "Kubernetes Policies"
type: "policies"
groups:
  - id: 5.1
    text: "RBAC and Service Accounts"
    checks:
      - id: 5.1.1
        text: "Ensure that the cluster-admin role is only used where required (Not Scored)"
        type: "manual"
        remediation: |
          Identify all clusterrolebindings to the cluster-admin role. Check if they are used and
          if they need this role or if they could use a role with fewer privileges.
          Where possible, first bind users to a lower privileged role and then remove the
          clusterrolebinding to the cluster-admin role :
          kubectl delete clusterrolebinding [name]          
        scored: false

      - id: 5.1.2
        text: "Minimize access to secrets (Not Scored)"
        type: "manual"
        remediation: |
          Where possible, remove get, list and watch access to secret objects in the cluster.          
        scored: false

      - id: 5.1.3
        text: "Minimize wildcard use in Roles and ClusterRoles (Not Scored)"
        type: "manual"
        remediation: |
          Where possible replace any use of wildcards in clusterroles and roles with specific
          objects or actions.          
        scored: false

      - id: 5.1.4
        text: "Minimize access to create pods (Not Scored)"
        type: "manual"
        Remediation: |
          Where possible, remove create access to pod objects in the cluster.          
        scored: false

      - id: 5.1.5
        text: "Ensure that default service accounts are not actively used. (Scored)"
        type: "manual"
        remediation: |
          Create explicit service accounts wherever a Kubernetes workload requires specific access
          to the Kubernetes API server.
          Modify the configuration of each default service account to include this value
          automountServiceAccountToken: false          
        scored: true

      - id: 5.1.6
        text: "Ensure that Service Account Tokens are only mounted where necessary (Not Scored)"
        type: "manual"
        remediation: |
          Modify the definition of pods and service accounts which do not need to mount service
          account tokens to disable it.          
        scored: false

  - id: 5.2
    text: "Pod Security Policies"
    checks:
      - id: 5.2.1
        text: "Minimize the admission of privileged containers (Not Scored)"
        type: "manual"
        remediation: |
          Create a PSP as described in the Kubernetes documentation, ensuring that
          the .spec.privileged field is omitted or set to false.          
        scored: false

      - id: 5.2.2
        text: "Minimize the admission of containers wishing to share the host process ID namespace (Scored)"
        type: "manual"
        remediation: |
          Create a PSP as described in the Kubernetes documentation, ensuring that the
          .spec.hostPID field is omitted or set to false.          
        scored: true

      - id: 5.2.3
        text: "Minimize the admission of containers wishing to share the host IPC namespace (Scored)"
        type: "manual"
        remediation: |
          Create a PSP as described in the Kubernetes documentation, ensuring that the
          .spec.hostIPC field is omitted or set to false.          
        scored: true

      - id: 5.2.4
        text: "Minimize the admission of containers wishing to share the host network namespace (Scored)"
        type: "manual"
        remediation: |
          Create a PSP as described in the Kubernetes documentation, ensuring that the
          .spec.hostNetwork field is omitted or set to false.          
        scored: true

      - id: 5.2.5
        text: "Minimize the admission of containers with allowPrivilegeEscalation (Scored)"
        type: "manual"
        remediation: |
          Create a PSP as described in the Kubernetes documentation, ensuring that the
          .spec.allowPrivilegeEscalation field is omitted or set to false.          
        scored: true

      - id: 5.2.6
        text: "Minimize the admission of root containers (Scored)"
        type: "manual"
        remediation: |
          Create a PSP as described in the Kubernetes documentation, ensuring that the
          .spec.runAsUser.rule is set to either MustRunAsNonRoot or MustRunAs with the range of
          UIDs not including 0.          
        scored: true

      - id: 5.2.7
        text: "Minimize the admission of containers with the NET_RAW capability (Scored)"
        type: "manual"
        remediation: |
          Create a PSP as described in the Kubernetes documentation, ensuring that the
          .spec.requiredDropCapabilities is set to include either NET_RAW or ALL.          
        scored: true

      - id: 5.2.8
        text: "Minimize the admission of containers with added capabilities (Scored)"
        type: "manual"
        remediation: |
          Ensure that allowedCapabilities is not present in PSPs for the cluster unless
          it is set to an empty array.          
        scored: true

      - id: 5.2.9
        text: "Minimize the admission of containers with capabilities assigned (Scored) "
        type: "manual"
        remediation: |
          Review the use of capabilites in applications runnning on your cluster. Where a namespace
          contains applications which do not require any Linux capabities to operate consider adding
          a PSP which forbids the admission of containers which do not drop all capabilities.          
        scored: true

  - id: 5.3
    text: "Network Policies and CNI"
    checks:
      - id: 5.3.1
        text: "Ensure that the CNI in use supports Network Policies (Not Scored)"
        type: "manual"
        remediation: |
          To use a CNI plugin with Network Policy, enable Network Policy in GKE, and the CNI plugin
          will be updated. See Recommendation 6.6.7.          
        scored: false

      - id: 5.3.2
        text: "Ensure that all Namespaces have Network Policies defined (Scored)"
        type: "manual"
        remediation: |
          Follow the documentation and create NetworkPolicy objects as you need them.          
        scored: true

  - id: 5.4
    text: "Secrets Management"
    checks:
      - id: 5.4.1
        text: "Prefer using secrets as files over secrets as environment variables (Not Scored)"
        type: "manual"
        remediation: |
          if possible, rewrite application code to read secrets from mounted secret files, rather than
          from environment variables.          
        scored: false

      - id: 5.4.2
        text: "Consider external secret storage (Not Scored)"
        type: "manual"
        remediation: |
          Refer to the secrets management options offered by your cloud provider or a third-party
          secrets management solution.          
        scored: false

  - id: 5.5
    text: "Extensible Admission Control"
    checks:
      - id: 5.5.1
        text: "Configure Image Provenance using ImagePolicyWebhook admission controller (Not Scored)"
        type: "manual"
        remediation: |
          Follow the Kubernetes documentation and setup image provenance.
          See also Recommendation 6.10.5 for GKE specifically.          
        scored: false

  - id: 5.6
    text: "General Policies"
    checks:
      - id: 5.6.1
        text: "Create administrative boundaries between resources using namespaces (Not Scored)"
        type: "manual"
        remediation: |
          Follow the documentation and create namespaces for objects in your deployment as you need
          them.          
        scored: false

      - id: 5.6.2
        text: "Ensure that the seccomp profile is set to docker/default in your pod definitions (Not Scored)"
        type: "manual"
        remediation: |
          Seccomp is an alpha feature currently. By default, all alpha features are disabled. So, you
          would need to enable alpha features in the apiserver by passing "--feature-
          gates=AllAlpha=true" argument.
          Edit the /etc/kubernetes/apiserver file on the master node and set the KUBE_API_ARGS
          parameter to "--feature-gates=AllAlpha=true"
          KUBE_API_ARGS="--feature-gates=AllAlpha=true"
          Based on your system, restart the kube-apiserver service. For example:
          systemctl restart kube-apiserver.service
          Use annotations to enable the docker/default seccomp profile in your pod definitions. An
          example is as below:
          apiVersion: v1
          kind: Pod
          metadata:
            name: trustworthy-pod
            annotations:
              seccomp.security.alpha.kubernetes.io/pod: docker/default
          spec:
            containers:
              - name: trustworthy-container
                image: sotrustworthy:latest          
        scored: false

      - id: 5.6.3
        text: "Apply Security Context to Your Pods and Containers (Not Scored)"
        type: "manual"
        remediation: |
          Follow the Kubernetes documentation and apply security contexts to your pods. For a
          suggested list of security contexts, you may refer to the CIS Security Benchmark for Docker
          Containers.          
        scored: false

      - id: 5.6.4
        text: "The default namespace should not be used (Scored)"
        type: "manual"
        remediation: |
          Ensure that namespaces are created to allow for appropriate segregation of Kubernetes
          resources and that all new resources are created in a specific namespace.          
        scored: true