A patch issued by Apple Computer last week failed to fix the underlying problem

Mac OS fix fails to plug security hole - News - ZDNet:
"A security hole still threatens Mac OS X users after a patch issued by Apple Computer last week failed to fix the underlying problem, security experts said on Tuesday.

The security issue could allow an attacker to transfer and then run a malicious program on a Mac, if the Mac's user can be enticed to go to a fake Web page on which the program has been placed.… "

http://zdnet.com.com/2100-1105_2-5220285.html