VM images built with Kubernetes Image Builder Nutanix or OVA providers use default credentials for Windows images if user did not override

Vulnerability Description

A security issue was discovered in the Kubernetes Image Builder where default credentials are enabled during the Windows image build process when using the Nutanix or VMware OVA providers. These credentials, which allow root access, are disabled at the conclusion of the build. Kubernetes clusters are only affected if their nodes use VM images created via the Image Builder project and the vulnerability was exploited during the build process, which requires an attacker to access the build VM and modify the image while the build is in progress.

References

• https://groups.google.com/g/kubernetes-security-announce/c/tuEsLUQu_PA
• https://github.com/kubernetes/kubernetes/issues/133115