Rafal Wojtczuk paper about the exploitation of a XEN vulnerability
The Evil Hacker escapes from DomU and gets into Dom0. Using clever
ret-into-libc technique he succeeds with his attack on x86 architecture,
despite the NX and ASLR deployed in Dom0 OS (Fedora Core 8). The Evil
Hacker is also not discouraged by the fact that the target
OS has SELinux protection enabled - he demonstrates how the particular
SELinux policy for Xen, used by default on FC8, can be bypassed.
Ultimately he gets full root access in Dom0. Rafal also discusses
variation of the exploitation on x86_64 architecture - he partially
succeeds, but his x64 exploit doesn't work in certain circumstances.