Chapter 7. Scan pod images with the Container Security Operator

Using the Container Security Operator, (CSO) you can scan container images associated with active pods, running on OpenShift (4.2 or later) and other Kubernetes platforms, for known vulnerabilities. The CSO:

  • Watches containers associated with pods on all or specified namespaces
  • Queries the container registry where the containers came from for vulnerability information provided an image’s registry supports image scanning (such as a Quay registry with Clair scanning)
  • Exposes vulnerabilities via the ImageManifestVuln object in the Kubernetes API

Using the instructions here, the CSO is installed in the marketplace-operators namespace, so it is available to all namespaces on your OpenShift cluster.

Note

To see instructions on installing the CSO on Kubernetes, select the Install button from the Container Security OperatorHub.io page.

7.1. Run the CSO in OpenShift

To start using the CSO in OpenShift, do the following:

  1. Go to Operators → OperatorHub (select Security) to see the available Container Security Operator.
  2. Select the Container Security Operator, then select Install to go to the Create Operator Subscription page.
  3. Check the settings (all namespaces and automatic approval strategy, by default), and select Subscribe. The Container Security appears after a few moments on the Installed Operators screen.

  4. Optionally, you can add custom certificates to the CSO. In this example, create a certificate named quay.crt in the current directory. Then run the following command to add the cert to the CSO (restart the Operator pod for the new certs to take effect): 

    $ oc create secret generic container-security-operator-extra-certs --from-file=quay.crt -n openshift-operators

  5. Open the OpenShift Dashboard (Home → Dashboards). A link to Image Security appears under the status section, with a listing of the number of vulnerabilities found so far. Select the link to see a Security breakdown, as shown in the following figure:

    Access SCO scanning data from OpenShift dashboard

  6. You can do one of two things at this point to follow up on any detected vulnerabilities:

    • Select the link to the vulnerability. You are taken to the container registry, Red Hat Quay or other registry where the container came from, where you can see information about the vulnerability. The following figure shows an example of detected vulnerabilities from a Quay.io registry:

      The CSO points you to a registry containing the vulnerable image

    • Select the namespaces link to go to the ImageManifestVuln screen, where you can see the name of the selected image and all namespaces where that image is running. The following figure indicates that a particular vulnerable image is running in two namespaces:

      View namespaces a vulnerable image is running in

At this point, you know what images are vulnerable, what you need to do to fix those vulnerabilities, and every namespace that the image was run in. So you can:

  • Alert anyone running the image that they need to correct the vulnerability
  • Stop the images from running (by deleting the deployment or other object that started the pod the image is in)

Note that if you do delete the pod, it may take a few minutes for the vulnerability to reset on the dashboard.

7.2. Query image vulnerabilities from the CLI

You can query information on security from the command line. To query for detected vulnerabilities, type: 

$ oc get vuln --all-namespaces
NAMESPACE     NAME              AGE
default       sha256.ca90...    6m56s
skynet        sha256.ca90...    9m37s

To display details for a particular vulnerability, identify one of the vulnerabilities, along with its namespace and the describe option. This example shows an active container whose image includes an RPM package with a vulnerability: 

$ oc describe vuln --namespace mynamespace sha256.ac50e3752...
Name:         sha256.ac50e3752...
Namespace:    quay-enterprise
...
Spec:
  Features:
    Name:            nss-util
    Namespace Name:  centos:7
    Version:         3.44.0-3.el7
    Versionformat:   rpm
    Vulnerabilities:
      Description: Network Security Services (NSS) is a set of libraries...