qemu-nbd in QEMU, as used in Xen 4.2.x, determines the format of a raw disk image based on the header, which allows local guest OS administrators to read arbitrary files on the host by modifying the header to identify a different format, which is used when the guest is restarted, a different vulnerability than CVE-2008-2004.
lists.fedoraproject.org/pipermail/package-announce/2013-April/103621.html
lists.fedoraproject.org/pipermail/package-announce/2013-April/103637.html
lists.fedoraproject.org/pipermail/package-announce/2013-April/104036.html
secunia.com/advisories/55082
security.gentoo.org/glsa/glsa-201309-24.xml
www.openwall.com/lists/oss-security/2013/04/15/3
www.openwall.com/lists/oss-security/2013/04/16/2
www.securitytracker.com/id/1028426