This is the last part of our blogpost series about Xen security [1] [2]. This time we write about a vulnerability we found (XSA-182) [0] (CVE-2016-6258) and his exploitation on Qubes OS [3] project.

This blog post describes the exploitation of Xen Security Advisory 148 (XSA-148) [1] (CVE-2015-7835). It has been discovered by Shangcong Luan of Alibaba and publicly disclosed in October 2015. At the time, we were working on writing an exploit and no public proof of concept nor exploit were available. Today, the security researcher responsible of the vulnerability disclosure has given a public talk [6] and will give conferences explaining his approach [7]. We decided to publish this blogpost anyway because our exploitation strategy is a little bit different.