vBulletin 3.6.10/3.7 RC4 is fixing a CSRF security issue. Version 5.0.8 also applies this security fix to DownloadsII. We advise you to upgrade as fast as possible.
More information about the CSRF security issue can be found in the announcement thread of vBulletin 3.6.10:
http://www.vbulletin.com/forum/showthread.php?t=268123
DownloadsII 5.0.8 Changelog
Jelle- Included the CSRF security fix from vBulletin 3.6.10/3.7 RC4