Canonical has announced the return of the Ubuntu forums to normal service; there is also a detailed description of how the system was compromised. “In summary, the root cause was a combination of a compromised individual account and the configuration settings in vBulletin, the Forums application software. There was no compromise of Ubuntu itself, or any other Canonical or Ubuntu services. We have repaired and hardened the Ubuntu Forums, and as the problematic settings are the default behaviour in vBulletin, we are working with vBulletin staff to change and/or better document these settings.” It all started with a cross-site scripting attack.