Important: xen security update

Updated xen packages that fix one security issue are now available for
Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having
important security impact. A Common Vulnerability Scoring System (CVSS)
base score, which gives a detailed severity rating, is available from the
CVE link in the References section.

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 QEMU emulated the e1000 network interface card
when the host was configured to accept jumbo network frames, and a
fully-virtualized guest using the e1000 emulated driver was not. A remote
attacker could use this flaw to crash the guest or, potentially, execute
arbitrary code with root privileges in the guest. (CVE-2012-6075)

All users of xen are advised to upgrade to these updated packages, which
correct this issue. After installing the updated packages, all running
fully-virtualized guests must be restarted for this update to take effect.

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

889301 - CVE-2012-6075 qemu: e1000 driver buffer overflow when processing large packets when SBP and LPE flags are disabled

https://www.redhat.com/security/data/cve/CVE-2012-6075.html
https://access.redhat.com/security/updates/classification/#important