The HVMOP_pagetable_dying hypercall in Xen 4.0, 4.1, and 4.2 does not properly check the pagetable state when running on shadow pagetables, which allows a local HVM guest OS to cause a denial of service (hypervisor crash) via unspecified vectors.
https://security.gentoo.org/glsa/201604-03
https://exchange.xforce.ibmcloud.com/vulnerabilities/80025
http://www.securitytracker.com/id?1027762
http://www.securityfocus.com/bid/56498
http://www.openwall.com/lists/oss-security/2012/11/13/3
http://www.debian.org/security/2012/dsa-2582
http://security.gentoo.org/glsa/glsa-201309-24.xml
http://secunia.com/advisories/55082
http://secunia.com/advisories/51468
http://secunia.com/advisories/51413
http://secunia.com/advisories/51352
http://secunia.com/advisories/51324
http://secunia.com/advisories/51200
http://lists.xen.org/archives/html/xen-announce/2012-11/msg00004.html
http://lists.opensuse.org/opensuse-security-announce/2014-03/msg00021.html
http://lists.opensuse.org/opensuse-security-announce/2012-12/msg00001.html
http://lists.opensuse.org/opensuse-security-announce/2012-11/msg00018.html
http://lists.opensuse.org/opensuse-security-announce/2012-11/msg00017.html
http://lists.opensuse.org/opensuse-security-announce/2012-11/msg00009.html
http://lists.opensuse.org/opensuse-security-announce/2012-11/msg00008.html