← Back to Red Hat OpenShift Container Platform 4.12 Security Technical Implementation Guide

V-257537

CAT II (Medium)

OpenShift must verify container images.

Rule ID

SV-257537r1015794_rule

STIG

Red Hat OpenShift Container Platform 4.12 Security Technical Implementation Guide

Version

V2R2

CCIs

CCI-003992

Discussion

The container platform must be capable of validating that container images are signed and that the digital signature is from a recognized and source approved by the organization. Allowing any container image to be introduced into the registry and instantiated into a container can allow for services to be introduced that are not trusted and may contain malicious code, which introduces unwanted services. These unwanted services can cause harm and security risks to the hosting server, the container platform, other services running within the container platform, and the overall organization.

Check Content

Determine if a policy has been put in place by running the following command:

for node in $(oc get node -oname); do oc debug $node -- chroot /host /bin/bash -c 'echo -n "$HOSTNAME "; cat /etc/containers/policy.json' 2>/dev/null; done

If the policy is not set to "reject" by default, or the signature keys are not configure appropriately on the registries, this is a finding.

The following is an example of how this will look on a system using Red Hat's public registries:

  <pre>
    {
  "default": [{"type": "reject"}],
  "transports": {
    "docker": {
      "registry.access.redhat.com": [
        {
          "type": "signedBy",
          "keyType": "GPGKeys",
          "keyPath": "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"
        }
      ],
      "registry.redhat.io": [
        {
          "type": "signedBy",
          "keyType": "GPGKeys",
          "keyPath": "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release"
        }
      ],

      ...
    }

Fix Text

Configure the OpenShift Container policy to validate that image signatures are verified and enforced by executing the following:
Note: This can be configured manually or through the use of the MachineConfig Operator published by Red Hat.

for mcpool in $(oc get mcp -oname | sed "s:.*/::" ); do
echo "apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: $mcpool
  name: 51-rh-registry-trust-$mcpool
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
      - contents:
          source: data:text/plain;charset=utf-8;base64,LS0tCmRvY2tlcjoKICByZWdpc3RyeS5hY2Nlc3MucmVkaGF0LmNvbToKICAgIHNpZ3N0b3JlOiBodHRwczovL2FjY2Vzcy5yZWRoYXQuY29tL3dlYmFzc2V0cy9kb2NrZXIvY29udGVudC9zaWdzdG9yZQo=
          verification: {}
        filesystem: root
        mode: 420
        path: /etc/containers/registries.d/registry.access.redhat.com.yaml
      - contents:
          source: data:text/plain;charset=utf-8;base64,LS0tCmRvY2tlcjoKICByZWdpc3RyeS5yZWRoYXQuaW86CiAgICBzaWdzdG9yZTogaHR0cHM6Ly9yZWdpc3RyeS5yZWRoYXQuaW8vY29udGFpbmVycy9zaWdzdG9yZQo=
          verification: {}
        filesystem: root
        mode: 420
        path: /etc/containers/registries.d/registry.redhat.io.yaml
      - contents:
          source: data:text/plain;charset=utf-8;base64,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
          verification: {}
        filesystem: root
        mode: 420
        path: /etc/containers/policy.json
" | oc apply -f -
done