lacework-global-342

note

This policy has been deprecated in favor of lacework-global-653.

See Adjusted Rules - CIS Amazon EKS 1.1.0 for further details.

4.2.6 Minimize the admission of root containers (Automated)

Profile Applicability

• Level 2

Description

Do not generally permit containers to be run as the root user.

Rationale

Containers may run as any Linux user. Containers which run as the root user, whilst constrained by Container Runtime security features still have an escalated likelihood of container breakout.

Ideally, all containers should run as a defined non-UID 0 user.

There should be at least one PodSecurityPolicy (PSP) defined which does not permit root users in a container.

If you need to run root containers, this should be defined in a separate PSP and you should carefully check RBAC controls to ensure that only limited service accounts and users are given permission to access that PSP.

Impact

Pods with containers which run as the root user will not be permitted.

Audit

Get the set of PSPs with the following command:

kubectl get psp

For each PSP, check whether running containers as root is enabled:

kubectl get psp <name> -o=jsonpath='{.spec.runAsUser.rule}'

Verify that there is at least one PSP which returns MustRunAsNonRoot or MustRunAs with the range of UIDs not including 0.

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.

References

https://kubernetes.io/docs/concepts/policy/pod-security-policy/#enabling-pod-security-policies