Yeah this is off topic, but I know there are a lot of IRC server admins on here, so I think this will help stop the spread of this exploit. Syzop has written a little module that will detect the bad DCC send and block it from ever reaching the user. I strongly recommend that if you run UnrealIRCd you install this module to protect your users!
(Sorry if anyone considers this to be spamming, I'm just trying to help stop this exploit from doing more damage than it has already done).
You can get the module at http://www.vulnscan.org/UnrealIrcd/modules/AntiDCCBug-latest.tar.gz