KVM 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 handled VSC_ATR messages when a guest was configured for a CCID USB smart card reader in passthrough mode. An attacker able to connect to the port on the host being used for such a device could use this flaw to crash the qemu-kvm process on the host or, possibly, escalate their privileges on the host. All users of qemu-kvm should upgrade to these updated packages, which contain a backported patch to resolve 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.