(RHSA-2012:1130) Moderate: xen security update

The xen packages contain administration tools and the xend service for
managing the kernel-xen kernel for virtualization on Red Hat Enterprise
Linux.

A flaw was found in the way the pyGrub boot loader handled compressed
kernel images. A privileged guest user in a para-virtualized guest (a DomU)
could use this flaw to create a crafted kernel image that, when attempting
to boot it, could result in an out-of-memory condition in the privileged
domain (the Dom0). (CVE-2012-2625)

Red Hat would like to thank Xinli Niu for reporting this issue.

All users of xen are advised to upgrade to these updated packages, which
contain a backported patch to correct this issue. After installing the
updated packages, the xend service must be restarted for this update to
take effect.