---
controls:
version: "rke-cis-1.24"
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 (Manual)"
        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 (Manual)"
        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 (Manual)"
        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 (Manual)"
        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. (Manual)"
        type: "manual"
        audit: check_for_default_sa.sh
        tests:
          test_items:
            - flag: "true"
              compare:
                op: eq
                value: "true"
              set: true
        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: false

      - id: 5.1.6
        text: "Ensure that Service Account Tokens are only mounted where necessary (Manual)"
        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: 5.1.7
        text: "Avoid use of system:masters group (Manual)"
        type: "manual"
        remediation: |
          Remove the system:masters group from all users in the cluster.
        scored: false

      - id: 5.1.8
        text: "Limit use of the Bind, Impersonate and Escalate permissions in the Kubernetes cluster (Manual)"
        type: "manual"
        remediation: |
          Where possible, remove the impersonate, bind and escalate rights from subjects.
        scored: false

  - id: 5.2
    text: "Pod Security Standards"
    checks:
      - id: 5.2.1
        text: "Ensure that the cluster has at least one active policy control mechanism in place (Manual)"
        type: "manual"
        remediation: |
          Ensure that either Pod Security Admission or an external policy control system is in place
          for every namespace which contains user workloads.
        scored: false

      - id: 5.2.2
        text: "Minimize the admission of privileged containers (Manual)"
        type: "manual"
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of privileged containers.
        scored: false

      - id: 5.2.3
        text: "Minimize the admission of containers wishing to share the host process ID namespace (Automated)"
        audit: |
          kubectl get psp -o json | jq .items[] | jq -r 'select((.spec.hostPID == null) or (.spec.hostPID == false))' | jq .metadata.name | wc -l | xargs -I {} echo '--count={}'
        tests:
          bin_op: or
          test_items:
            - flag: "kubectl: not found"
            - flag: "jq: not found"
            - flag: count
              compare:
                op: gt
                value: 0
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of `hostPID` containers.
        scored: true

      - id: 5.2.4
        text: "Minimize the admission of containers wishing to share the host IPC namespace (Automated)"
        audit: |
          kubectl get psp -o json | jq .items[] | jq -r 'select((.spec.hostIPC == null) or (.spec.hostIPC == false))' | jq .metadata.name | wc -l | xargs -I {} echo '--count={}'
        tests:
          bin_op: or
          test_items:
            - flag: "kubectl: not found"
            - flag: "jq: not found"
            - flag: count
              compare:
                op: gt
                value: 0
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of `hostIPC` containers.
        scored: true

      - id: 5.2.5
        text: "Minimize the admission of containers wishing to share the host network namespace (Automated)"
        audit: |
          kubectl get psp -o json | jq .items[] | jq -r 'select((.spec.hostNetwork == null) or (.spec.hostNetwork == false))' | jq .metadata.name | wc -l | xargs -I {} echo '--count={}'
        tests:
          bin_op: or
          test_items:
            - flag: "kubectl: not found"
            - flag: "jq: not found"
            - flag: count
              compare:
                op: gt
                value: 0
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of `hostNetwork` containers.
        scored: true

      - id: 5.2.6
        text: "Minimize the admission of containers with allowPrivilegeEscalation (Automated)"
        audit: |
          kubectl get psp -o json | jq .items[] | jq -r 'select((.spec.allowPrivilegeEscalation == null) or (.spec.allowPrivilegeEscalation == false))' | jq .metadata.name | wc -l | xargs -I {} echo '--count={}'
        tests:
          bin_op: or
          test_items:
            - flag: "kubectl: not found"
            - flag: "jq: not found"
            - flag: count
              compare:
                op: gt
                value: 0
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of containers with `.spec.allowPrivilegeEscalation` set to `true`.
        scored: true

      - id: 5.2.7
        text: "Minimize the admission of root containers (Manual)"
        type: "manual"
        remediation: |
          Create a policy for each namespace in the cluster, ensuring that either `MustRunAsNonRoot`
          or `MustRunAs` with the range of UIDs not including 0, is set.
        scored: false

      - id: 5.2.8
        text: "Minimize the admission of containers with the NET_RAW capability (Manual)"
        type: "manual"
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of containers with the `NET_RAW` capability.
        scored: false

      - id: 5.2.9
        text: "Minimize the admission of containers with added capabilities (Manual)"
        type: "manual"
        remediation: |
          Ensure that `allowedCapabilities` is not present in policies for the cluster unless
          it is set to an empty array.
        scored: false

      - id: 5.2.10
        text: "Minimize the admission of containers with capabilities assigned (Manual)"
        type: "manual"
        remediation: |
          Review the use of capabilites in applications running on your cluster. Where a namespace
          contains applicaions 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: false

      - id: 5.2.11
        text: "Minimize the admission of Windows HostProcess containers (Manual)"
        type: "manual"
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of containers that have `.securityContext.windowsOptions.hostProcess` set to `true`.
        scored: false

      - id: 5.2.12
        text: "Minimize the admission of HostPath volumes (Manual)"
        type: "manual"
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of containers with `hostPath` volumes.
        scored: false

      - id: 5.2.13
        text: "Minimize the admission of containers which use HostPorts (Manual)"
        type: "manual"
        remediation: |
          Add policies to each namespace in the cluster which has user workloads to restrict the
          admission of containers which use `hostPort` sections.
        scored: false

  - id: 5.3
    text: "Network Policies and CNI"
    checks:
      - id: 5.3.1
        text: "Ensure that the CNI in use supports NetworkPolicies (Manual)"
        type: "manual"
        remediation: |
          If the CNI plugin in use does not support network policies, consideration should be given to
          making use of a different plugin, or finding an alternate mechanism for restricting traffic
          in the Kubernetes cluster.
        scored: false

      - id: 5.3.2
        text: "Ensure that all Namespaces have NetworkPolicies defined (Manual)"
        type: "skip"
        remediation: |
          Follow the documentation and create NetworkPolicy objects as you need them.
        scored: false

  - id: 5.4
    text: "Secrets Management"
    checks:
      - id: 5.4.1
        text: "Prefer using Secrets as files over Secrets as environment variables (Manual)"
        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 (Manual)"
        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 (Manual)"
        type: "manual"
        remediation: |
          Follow the Kubernetes documentation and setup image provenance.
        scored: false

  - id: 5.7
    text: "General Policies"
    checks:
      - id: 5.7.1
        text: "Create administrative boundaries between resources using namespaces (Manual)"
        type: "manual"
        remediation: |
          Follow the documentation and create namespaces for objects in your deployment as you need
          them.
        scored: false

      - id: 5.7.2
        text: "Ensure that the seccomp profile is set to docker/default in your Pod definitions (Manual)"
        type: "manual"
        remediation: |
          Use `securityContext` to enable the docker/default seccomp profile in your pod definitions.
          An example is as below:
            securityContext:
              seccompProfile:
                type: RuntimeDefault
        scored: false

      - id: 5.7.3
        text: "Apply SecurityContext to your Pods and Containers (Manual)"
        type: "manual"
        remediation: |
          Follow the Kubernetes documentation and apply SecurityContexts to your Pods. For a
          suggested list of SecurityContexts, you may refer to the CIS Security Benchmark for Docker
          Containers.
        scored: false

      - id: 5.7.4
        text: "The default namespace should not be used (Automated)"
        audit: |
          #!/bin/bash
          set -eE
          handle_error() {
              echo "false"
          }
          trap 'handle_error' ERR
          count=$(kubectl get all -n default -o json | jq .items[] | jq -r 'select((.metadata.name!="kubernetes"))' | jq .metadata.name | wc -l)
          if [[ ${count} -gt 0 ]]; then
              echo "false"
              exit
          fi
          echo "true"
        tests:
          bin_op: or
          test_items:
            - flag: "kubectl: not found"
            - flag: "jq: not found"
            - flag: "true"
        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