KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. The qemu-kvm package provides the user-space component for running virtual machines using KVM.
A heap buffer overflow flaw was found in the way QEMU's NE2000 NIC emulation implementation handled certain packets received over the network. A privileged user inside a guest could use this flaw to crash the QEMU instance (denial of service) or potentially execute arbitrary code on the host. (CVE-2015-5279)
Red Hat would like to thank Qinghao Tang of QIHU 360 Inc. for reporting this issue.
All qemu-kvm users are advised to upgrade to these updated packages, which contain a backported patch 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.