C-0276 - Minimize the admission of containers wishing to share the host IPC namespace

Framework

cis-v1.10.0

Severity

Medium

Description of the the issue

A container running in the host's IPC namespace can use IPC to interact with processes outside the container.

There should be at least one admission control policy defined which does not permit containers to share the host IPC namespace.

If you need to run containers which require hostIPC, this should be definited in a separate policy and you should carefully check to ensure that only limited service accounts and users are given permission to use that policy.

Related resources

CronJob, DaemonSet, Deployment, Job, Pod, ReplicaSet, StatefulSet

What does this control test

Do not generally permit containers to be run with the hostIPC flag set to true.

How to check it manually

To fetch hostIPC from each pod.

get pods -A -o=jsonpath=$'{range .items[*]}{@.metadata.name}: {@.spec.hostIPC}
{end}'

Remediation

Add policies to each namespace in the cluster which has user workloads to restrict the admission of hostIPC containers.

Impact Statement

Pods defined with spec.hostIPC: true will not be permitted unless they are run under a specific policy.

Default Value

By default, there are no restrictions on the creation of hostIPC containers.

Example

No example