Microsoft Says Internet Explorer 9 Doesn't Have Pwn2Own Bug

The vulnerability in Internet Explorer 8 that researcher Stephen Fewer exploited at the Pwn2Own hacking contest this week has already been fixed in Internet Explorer, according to Microsoft.

During the CanSecWest Pwn2Own challenge, Fewer chained three different vulnerabilities to hack into IE8 on a fully patched Windows 7 machine. The attack also included a way to escape the Protected Mode sandbox. Microsoft checked the release candidate and RTM versions of Internet Explorer 9 and confirmed that the remote code execution issue Fewer found does not exist in the latest version, Microsoft said March 11. "As ths vulnerability does not affect IE9, Microsoft encourages customers to take advantage of the security improvements offered by the browser," Microsoft said. Internet Explorer 9 is slated for final release on March 14. Microsoft also confirmed two additional flaws used at Pwn2Own, but did not say if they were also patched in IE9.

Microsoft is looking at patching the earlier versions of Internet Explorer, but did not say when the fixes will be released for those versions. The overwhelming majority of users will either have to upgrade to the IE9 browser or keep working with the unpatched browser and hope Microsoft gets around to patching it or that someone else with malicious intent doesn't stumble upon the vulnerabilities.

If Microsoft sticks to its existing timetable of patching its browser on even-numbered months, then the first opportunity for the patch will be in April's Patch Tuesday update.

Under contest rules, the vulnerabilities and exploits used at Pwn2Own are legally the property of TippingPoint ZDI, the contest's sponsor. Researchers are forbidden from publishing or in any way publicly disclosing the information. TippingPoint provides all the information directly to the vendor and gives them six months to fix the issue.

"We appreciate ZDI's practice of disclosing vulnerabilities directly to affected software companies and the opportunity to continually improve the security of Microsoft's products," the company said.

On the first day of Pwn2Own, a team of security researchers from the French penetration test company VUPEN successfully exploited WebKit vulnerabilities in Safari to compromise a 64-bit version of a fully patched Mac OS X running on a MacBook. Fewer also hacked Internet Explorer on the same day. One researcher who signed up to take on Google Chrome didn't show up, and the other team decided to skip the contest in order to focus on the BlackBerry challenge on the following day.

That team went on to successfully exploit multiple WebKit vulnerabilities on a BlackBerry Torch 9800 on the second day of Pwn2Own. Charlie Miller, the researcher who'd won three previous years in a row, won again by exploiting another bug in Apple iPhone's MobileSafari browser. Ironically, the target iPhone was running iOS 4.2.1, not the latest iOS 4.3 Apple released on March 9. However, TippingPoint determined that the same bug existed in both versions, even though the exact exploit wouldn't work because Apple had introduced a new layer of security onto the platform.

Sam Thomas, the researcher scheduled to take on Firefox on March 10, withdrew at the last minute because his exploit was not stable, according to Jacinda Ann Mein, a TippingPoint spokesperson.

The "survivors" of the contest—Google Chrome, Android, Windows 7 and Mozilla Firefox—were not compromised simply because no security researcher attempted it on any of the three days of the contest.