cloudburst attack is more or less a fancy term for "Host code execution vulnerability from a guest operating system."
How do you protect against that? The same way you protect against every products security exploits, with updates/patches.
What does this means if you are using some virtual hosting provider (SaaS, PaaS, etc)? Pick one whose core virtualization technology is well tested. Xen would be a great candidate since it's open source and therefore receives external code reviews.
If you are implementing virtualization in house use the most recent stable version and implement any additional host protections possible, such as chroots, selinux, jails, kernel patches like grsec, etc.