(RHSA-2013:0609) Important: qemu-kvm security update

KVM (Kernel-based Virtual Machine) is a full virtualization solution for
Linux on AMD64 and Intel 64 systems. qemu-kvm is the user-space component
for running virtual machines using KVM.

A flaw was found in the way QEMU-KVM emulated the e1000 network interface
card when the host was configured to accept jumbo network frames, and a
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 qemu-kvm should upgrade to these updated packages, which
contain backported patches to correct this issue. After installing this
update, shut down all running virtual machines. Once all virtual machines
have shut down, start them again for this update to take effect.