Xen 4.0, and 4.1, when running a 64-bit PV guest on "older" AMD CPUs, does not properly protect against a certain AMD processor bug, which allows local guest OS users to cause a denial of service (host hang) via sequential execution of instructions across a non-canonical boundary, a different vulnerability than CVE-2012-0217.
http://lists.opensuse.org/opensuse-security-announce/2012-11/msg00017.html
http://lists.opensuse.org/opensuse-security-announce/2012-11/msg00018.html
http://lists.xen.org/archives/html/xen-announce/2012-06/msg00002.html
http://secunia.com/advisories/51413
http://secunia.com/advisories/55082
Published: 2012-12-03
Base Score: 1.9
Vector: CVSS2#AV:L/AC:M/Au:N/C:N/I:N/A:P
Severity: Low