The Ocaml xenstored implementation (oxenstored) in Xen 4.1.x, 4.2.x, and 4.3.x allows local guest domains to cause a denial of service (domain shutdown) via a large message reply.
http://www.securitytracker.com/id/1029264
http://www.securityfocus.com/bid/63404
http://www.openwall.com/lists/oss-security/2013/10/29/5
http://security.gentoo.org/glsa/glsa-201407-03.xml
http://lists.opensuse.org/opensuse-updates/2013-12/msg00059.html
http://lists.opensuse.org/opensuse-updates/2013-11/msg00009.html