Security Bulletin: Red Hat OpenShift on IBM Cloud is affected by a Kubernetes API server security vulnerability (CVE-2023-5408)

Summary

Red Hat OpenShift on IBM Cloud is affected by a security vulnerability in the Kubernetes API server that may allow an attacker to modify restricted node labels and bypass the node restriction admission plugin (CVE-2023-5408).

Vulnerability Details

CVEID: CVE-2023-5408
Description: OpenShift Kubernetes could allow a local authenticated attacker to gain elevated privileges on the system, caused by a flaw in the node restriction admission plugin. By sending a specially crafted request, an authenticated attacker could exploit this vulnerability to gain elevated privileges.
CVSS Base Score: 8.2
CVSS Temporal Score: <https://exchange.xforce.ibmcloud.com/vulnerabilities/270452&gt; for more information
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H)

Affected Products and Versions

Red Hat OpenShift on IBM Cloud 4.13.0-4.13.18
Red Hat OpenShift on IBM Cloud 4.12.0-4.12.42
Red Hat OpenShift on IBM Cloud 4.11.0-4.11.53
Red Hat OpenShift on IBM Cloud 3.11-4.10

Remediation/Fixes

Updates for Red Hat OpenShift on IBM Cloud clusters at version 4.11 or later are available that fix this vulnerability. Red Hat OpenShift on IBM Cloud will attempt to automatically apply the fix to your cluster master. There is no need to update cluster worker nodes for this vulnerability.

To verify your clusters are no longer exposed to this vulnerability, use the following IBM Cloud CLI command to confirm your cluster master versions:

ibmcloud oc clusters

If your cluster masters are at one of the following versions or later, they are no longer exposed to this vulnerability:

4.13.19
4.12.44
4.11.56

If one or more of your clusters has not had its master automatically updated then use the following IBM Cloud CLI command to complete the cluster master update, replacing 4.##_openshift with the target version.

ibmcloud oc cluster master update --cluster <cluster name or ID> --version 4.##_openshift

Customers running Red Hat OpenShift on IBM Cloud clusters at version 4.9 or 4.10 must upgrade to version 4.11. Please review the documentation before starting an upgrade since additional actions may be required.

Customers running Red Hat OpenShift on IBM Cloud clusters at version 4.8 or earlier must create a new cluster and deploy their apps to the new cluster.

Red Hat OpenShift on IBM Cloud versions 4.10 and earlier are no longer supported. See the Red Hat OpenShift on IBM Cloud version information and update actions documentation for more information about OpenShift versions and version support policies. For security reasons, IBM reserves the right to shut down the control planes of clusters running archived versions.