At CSA, I was talking about hypervisors, breakouts and an overview of security
measures to protect the host.
(Slides)
This ranged from the basic features some hypervisors provide out of the box to
advanced features like SELinux, device domain models and XSM-FLASK.
Most of the other talks were more targeted towards management level employees,
but even as a fairly technical person I found Mike Bursell’s
talk highly interesting. After my
talk about securing the host system from a malicious guest, he dealt with the
inverse: Technologies to protect a guest from a malicious or compromised host.
In the course of a current virtualization research project, I was reviewing a
lot of documentation on hypervisor security. While “hypervisor security” is a
very wide field, hypervisor breakouts are usually one of the most (intensely)
discussed topics. I don’t want to go down the road of rating the risk of
hypervisor breakouts and giving appropriate recommendations (even though we do
this on a regular base which, surprisingly often, leads to almost religious
debates. I know I say this way too often:I’ll cover this topic in a future post
;)), but share a few observations of analyzing well-known examples of
vulnerabilities that led to guest-to-host-escape scenarios. The following table
provides an overview of the vulnerabilities in question: