Security Bulletin: Red Hat OpenShift on IBM Cloud is affected by a Kubernetes API server security vulnerability (CVE-2019-11254)

Summary

Red Hat OpenShift on IBM Cloud is affected by a security vulnerability in the Kubernetes API server that could lead to a denial of service vulnerability from malicious YAML payloads (CVE-2019-11254)

Vulnerability Details

CVEID: CVE-2019-11254
Description: Kubernetes is vulnerable to a denial of service, caused by a flaw in kube-apiserver. By sending a specially-crafted request using YAML payloads, a remote authenticated attacker could exploit this vulnerability to consume excessive CPU cycles.
CVSS Base Score: 7.5
CVSS Temporal Score: <https://exchange.xforce.ibmcloud.com/vulnerabilities/178935&gt; for more information
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Affected Products and Versions

Red Hat OpenShift on IBM Cloud 3.11.0-3.11.231

Remediation/Fixes

Updates for Red Hat OpenShift on IBM Cloud clusters at version 3.11 are available that fix this vulnerability. Red Hat OpenShift on IBM Cloud service 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 version 3.11.232 or later, they are no longer exposed to this vulnerability:

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.

ibmcloud oc cluster master update --cluster <cluster name or ID> --version 3.11_openshift

Monitor IBM Cloud Status for Future Security Bulletins

Monitor the security notifications on the IBM Cloud Status page to be advised of future security bulletins.

References

Complete CVSS v3 Guide
On-line Calculator v3

Off

Kubernetes Security Announcement for CVE-2019-11254

Related Information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.

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