Blank passwords allowed unrestricted QEMU VNC session access.
Neil Wilson discovered that if VNC passwords were blank in QEMU configurations, access to VNC sessions was allowed without a password instead of being disabled. A remote attacker could connect to running VNC sessions of QEMU and directly control the system. By default, QEMU does not start VNC sessions.
14 February 2011
A security issue affects these releases of Ubuntu and its derivatives:
Blank passwords allowed unrestricted QEMU VNC session access.
Neil Wilson discovered that if VNC passwords were blank in QEMU configurations, access to VNC sessions was allowed without a password instead of being disabled. A remote attacker could connect to running VNC sessions of QEMU and directly control the system. By default, QEMU does not start VNC sessions.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
After a standard system update you need to restart any running QEMU sessions to make all the necessary changes.