Apple Inc. yesterday patched four flaws in its Safari browser, including the critical vulnerability used by a researcher last month to hack a MacBook Air and claim a $10,000 check at the "Pwn 2 Own" contest.
This is the second time in the past four weeks that Apple has patched its browser.
Safari 3.1.1, released on Wednesday in versions for both Mac OS X and Windows users, plugged four holes altogether. All were present in the Windows XP and Vista editions; the Mac version, however, sported just two.
WebKit is the open-source project that provides the core engine for Apple's browser, as well as rendering code for other Mac OS X applications, including Mail and Dashboard.
In exchange for the $10,000 prize awarded by 3Com Corp.'s TippingPoint unit, which runs a bug bounty program called the Zero Day Initiative (ZDI), Miller and his fellow researchers turned over the vulnerability and signed a nondisclosure agreement that prevented them from discussing their findings until the bug was patched.
Apple also patched a cross-site scripting vulnerability, an address-bar spoofing bug and a flaw in Safari's file downloading in the 3.1.1 release. The first was fixed in both the Mac and Windows versions, but the second and third existed only in the Windows edition.
Two of the four vulnerabilities were labeled as possibly leading to "arbitrary code execution," which is Apple's way of saying "critical."
Not surprisingly, Miller praised the Pwn 2 Own concept. "We wouldn't have looked for the bug if not for the contest," he said. "We found it, we reported it, and it's now fixed. It would still be in the WebKit code without the contest."
Safari 3.1.1 can be downloaded from Apple's Web site in versions for Mac OS X 10.4 (Tiger), Mac OS X 10.5 (Leopard), Windows XP and Windows Vista.