Virtualisation technology brings many benefits to IT managers, and by extension to business teams; flexibility, speed of deployment and better resource utilisation being the main success factors.
However, many security professionals have been asking the key questions: Is virtualisation moving security boundaries? Are different security controls required to those in traditional physical hardware environments?
Finding the answers is not that simple. One needs to understand virtualisation architectures to answer these questions.
For virtualisation to provide the same level of assurance as separate physical servers, the following requirements must be addressed:
- Trusted hardware architecture and implementation;
- Trusted hypervisor architecture and implementation;
- Trusted virtual hypervisor administration.
Are these available now? Not 100%, and as such, the same level of security cannot be achieved. However, we are getting very close, and the following control considerations will get you closer to achieving a reasonable level of assurance:
Read more about securing virtual environments
- Deploy hardware that supports Intel TXT or AMD TrustZone. This will satisfy the first requirements. Most of the hardware you can buy these days does support it, but it is worth checking. The kernel of the host operating system (OS) must also support this technology to get full advantage of the hardware and software integrity checks.
- Implement the latest versions of the hypervisor technologies. For compliance reasons, you should run generic and critical guest instances on separate hardware servers or blades.
- Verify that your hypervisor administrators, who hold the key to the security of your installation, are trustworthy. In some instances you may want to separate these into various groups, each responsible for a group of systems based on security classifications.
- Security suppliers are waking up to the hypervisor challenge, and many are introducing intrusion detection systems (IDS), antivirus, host firewall, and other products that are ready for hypervisor. It is worth asking your security suppliers for the roadmaps so you are prepared for the new versions.
In summary, virtualisation brings some level of compromise, at least for now. However, the systems can be secured reasonably well and virtualisation should be embraced.
Vladimir Jirasek is a member of the Cloud Security Alliance (UK).