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. Virtual Network Computing is a remote display system. A flaw was found in the way the VNC "password" option was handled. Clearing a password disabled VNC authentication, allowing a remote user able to connect to the virtual machines" VNC ports to open a VNC session without authentication. 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.