Windows 7: Microsoft confirms IE6, IE7 zero-day bug

Microsoft confirms IE6, IE7 zero-day bug

No word on patch plans; disable JavaScript, say researchers

By Gregg Keizer
November 23, 2009 04:03 PM ET

Computerworld - Microsoft today confirmed that exploit code published last week can compromise PCs running older versions of Internet Explorer (IE), but said its security team has not yet seen any in-the-wild attacks.

The attack code, which was posted Friday to the Bugtraq security mailing list, affects both Internet Explorer 6 (IE6) and the newer IE7, Microsoft acknowledged. "Microsoft can confirm that the publicly available exploit code affects IE6 and IE7, not IE8," a company spokesman said in an e-mail reply to questions today.

IE6 and IE7 account for more than 41% of all browsers used worldwide, according to the most recent data from metrics firm Net Applications. IE8, meanwhile, has an 18.1% market share.

Over the weekend, Symantec researchers took note of the exploit code, but said that it was shaky. "The exploit currently exhibits signs of poor reliability, but we expect that a fully-functional reliable exploit will be available in the near future," the security company's analysis team said in an entry on a company blog Saturday.

According to Danish vulnerability tracking vendor Secunia, the flaw is in IE's layout parser, and could be exploited by hackers to hijack fully-patched Windows XP Service Pack 3 (SP3) machines. Secunia rated the vulnerability as "highly critical," its second-highest threat ranking.