May 15, 2015

Hardening Hypervisors Against VENOM-Style Attacks

This is a guest blog post by Tamas K. Lengyel, a long-time open source enthusiast and Xen contributor. Tamas works as a Senior Security Researcher at Novetta, while finishing his PhD on the topic of malware analysis and virtualization security at the University of Connecticut.

The recent disclosure of the VENOM bug affecting major open-source hypervisors, such as KVM and Xen, has many reevaluating their risks when using cloud infrastructures. That is a very good thing indeed. Complex software systems are prone to bugs and errors.  Virtualization and the cloud have been erroneously considered by many to be a silver bullet against intrusions and malware. The fact is the cloud is anything but a safe place. There are inherent risks in the cloud and itâs very important to put those risks in their proper context.


VENOM is one of many vulnerabilities involving hypervisors (e.g. [Qemu][ESX],[KVM][Xen]). And, while Venom is indeed a serious bug and can result in a VM escape, which in turn can compromise all VMs on the host, it doesnât have to be. In fact, weâve known about VENOM-style attacks for a long time. Yet, there are easy-to-deploy counter-measures to mitigate the risk of such exploits natively available in both Xen and KVM (see RedHatâs blog post on the same topic).

Read more at Xen Project Blog.

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