Apple has released Safari 3.1.1 for Mac and Windows, a security update that fixes a vulnerability exploited in the recent Pwn2Own hacking contest at the CanSecWest conference (see "Apple Becomes First Victim in Hacking Contest," 2008-03-28). According to the security release notes for Safari 3.1.1, the update tackles the JavaScript weakness in WebKit exposed at the conference by "performing additional validation of JavaScript regular expressions" to prevent a heap buffer overflow.

A flaw where a colon character in a maliciously crafted URL could lead to a cross-site scripting attack has also been repaired. Two other fixes are specific to the Windows version of Safari: a timing issue that opened up control of the address bar and a memory corruption issue.

Safari 3.1.1 is available via Software Update or as a 39 MB download. It requires Mac OS X 10.4.11 or Mac OS X 10.5.2, or Windows XP or Vista on the PC.