A vulnerability has been detected in the GNU C library that is part of the Ubuntu operating system that VisibleThread runs on.
For more information on the vulnerability see https://wiki.ubuntu.com/SecurityTeam/KnowledgeBase/GHOST
VisibleThread and Clarity Grader cloud customers
Our operations team are currently working on patching our affected servers. Our cloud users will not be effected by this issue. We have no evidence to suggest that our VisibleThread servers were exploited by this vulnerability.
VisibleThread on-premise customers
Note: Your VisibleThread on-premise installation is self-contained and running behind your corporate firewall, so there is very little actual risk of being impacted by this issue
VisibleThread on-premise customers running the Ubuntu 12.04 LTS operating system can patch their systems using the following commands (note a reboot is required so there will be some downtime for the VisibleThread application).
As with any update, its a good idea to snapshot or backup your VisibleThread VM before applying this.
sudo apt-get update
sudo apt-get install libc6
sudo reboot now
Once the system has rebooted you can verify that the correct package has been installed:
dpkg -s libc6
This should output a version number which should read '2.15-0ubuntu10.10'