CVE 2010-1409
Incomplete blacklist vulnerability in WebKit in Apple Safari before 5.0 on Mac OS X 10.5 through 10.6 and Windows, and before 4.1 on Mac OS X 10.4, allows remote attackers to trigger disclosure of data over IRC via vectors involving an IRC service port.
See the 
CVE page on Mitre.org
for more details.
