High

Analysis Summary

A serious security vulnerability in the Kubernetes Image Builder has been found. In some cases, this vulnerability might be leveraged to obtain root access if successfully exploited. Version 0.1.38 fixes the issue, which is listed as CVE-2024-9486 (CVSS score: 9.8).

A vulnerability was identified in the Kubernetes Image Builder, wherein the image build process activates default credentials. Furthermore, nodes that use virtual machine images created with the Proxmox provider might still be able to use these default credentials because the images do not disable them. Root access can be obtained by using the credentials.

Having stated that, the vulnerability only affects Kubernetes clusters if virtual machine (VM) images generated by the Proxmox provider's Image Builder project are used by their nodes. Disabling the builder account on impacted virtual machines has been recommended as a temporary solution. It is also advised that users rebuild the impacted images using a patched version of Image Builder and then re-deploy them on virtual machines.

The Kubernetes team's update replaces the default credentials with a password that is created at random and set for the length of the image build. Additionally, when the image build process is complete, the builder account is disabled. A related issue (CVE-2024-9594, CVSS score: 6.3) with default credentials when image builds are made using the Nutanix, OVA, QEMU, or raw providers is also addressed in Kubernetes Image Builder version 0.1.38.

The reason CVE-2024-9594 has a lesser severity is that the VMs that use the images created by these providers are only impacted if an attacker managed to get into the VM where the image creation was taking place and leveraged the vulnerability to change the image while it was being constructed.

Impact

• Unauthorized Access
• Security Bypass

Indicators of Compromise

CVE

• CVE-2024-9486

Affected Vendors

Remediation

• Rebuild any affected images using a fixed version of Image Builder. Re-deploy the fixed images to any affected VMs.
• Organizations must test their assets for the vulnerability mentioned above and apply the available security patch or mitigation steps as soon as possible.
• Implement multi-factor authentication to add an extra layer of security to login processes.
• Regularly monitor network activity for any unusual behavior, as this may indicate that a cyberattack is underway.
• Organizations must stay vigilant and follow best practices for cybersecurity to protect their systems and data from potential threats. This includes regularly updating software and implementing strong access controls and monitoring tools.
• Develop a comprehensive incident response plan to respond effectively in case of a security breach or data leakage.
• Maintain regular backups of critical data and systems to ensure data recovery in case of a security incident.
• Adhere to security best practices, including the principle of least privilege, and ensure that users and applications have only the necessary permissions.
• Establish a robust patch management process to ensure that security patches are evaluated, tested, and applied promptly.
• Conduct security audits and assessments to evaluate the overall security posture of your systems and networks.
• Implement network segmentation to contain and isolate potential threats to limit their impact on critical systems.