CVE-2024-9486: Kubernetes Image Builder Security Vulnerability - Default Credentials in Proxmox Provider VM Images Result in Unauthorized Root Access

A new security issue (CVE-2024-9486) has been discovered in the Kubernetes Image Builder project, particularly affecting versions up to and including v.1.37. This vulnerability arises from the use of default credentials during the image build process. When creating virtual machine (VM) images using the Proxmox provider in Image Builder, these default credentials are not disabled, thus leaving the system at risk. Nodes using the vulnerable VM images can potentially be accessed via the default credentials, resulting in unauthorized root access. This issue affects Kubernetes clusters only when their nodes use VM images that were created via the Image Builder project with its Proxmox provider.

Code Snippet

A code snippet showcasing the use of default credentials in the image builder configuration.yaml file:

provider_settings:
  proxmox:
    username: 'root@pam'
    password: 'password123'
    ...

Note: The above code is just an example and should not be used in a live environment, as it presents a security risk due to the use of default credentials.

Kubernetes Image Builder GitHub Repository -

https://github.com/kubernetes-sigs/image-builder

Image Builder v.1.37 Release -

https://github.com/kubernetes-sigs/image-builder/releases/tag/v.1.37

Proxmox Virtual Environment -

https://www.proxmox.com/en/proxmox-ve

CVE-2024-9486 Details -

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-9486

Exploit Details

The Kubernetes Image Builder security vulnerability (CVE-2024-9486) can be exploited by an attacker who is aware of the default credentials in the configuration. Leveraging these hardcoded credentials, the attacker might gain unauthorized root access to the nodes running VM images created using the Image Builder project with its Proxmox provider.

To protect your Kubernetes cluster from being compromised, please follow the recommendations below

1. Upgrade the Image Builder: Ensure that you are using the latest version of the Kubernetes Image Builder in your environment. As of now, no new version has been released resolving this issue. However, it is essential to keep an eye on updates and apply them as soon as they become available.

2. Customize the Default Credentials: When using the Image Builder with the Proxmox provider, ensure that you change the default username, password, and other sensitive information in the configuration file. Customizing these default settings will help prevent unauthorized access to your nodes.

3. Monitor Access Logs: Regularly review the access logs for your nodes and VMs to identify any suspicious activity or unauthorized access attempts. Timely detection of potential security incidents may mitigate possible damage caused by an attacker exploiting the default credentials vulnerability.

Summary

In conclusion, it is crucial to stay informed about security issues like CVE-2024-9486 and to take the necessary steps to mitigate the risks associated with your Kubernetes clusters. By staying aware of the Image Builder project's updates, customizing default credentials, and closely monitoring access logs, you can better protect your environment from potential threats and vulnerabilities.

Timeline

Published on: 10/15/2024 21:15:11 UTC
Last modified on: 10/16/2024 16:38:14 UTC