Mac OS-X vulnerability problem

major_clanger points out a major vulnerability in Mac OS-X which I hadn't heard about before. Since we have mac-using friends which aren't in common I'm posting a link to his post, which in turn links to more detailed information.

http://www.livejournal.com/users/major_clanger/64265.html

Nice, in a way, that it isn't Windows for once, but I'd just as soon not be the bearer of bad news.