You may have heard in the news about the Shellshock bug, which affects Unix and Linux servers:
The good news is that the way PBworks’ systems are set up, the Shellshock bug could not be exploited. As a precaution, however, we have already applied multiple patches to all of our Linux servers to eliminate this vulnerability. As additional patches become available, we will implement them as well. Our service, and your data, are safe from this issue.