Posted by Virus Bulletin on Dec 16, 2008
Large numbers of users vulnerable to unpatched problem.
The as-yet unpatched vulnerability in Microsoft's Internet Explorer browser, reported last week and coinciding with the release of the monthly 'Patch Tuesday' security updates, is becoming more serious by the day as more and more infected websites appear to be attempting to exploit the flaw to gain access to visitors' systems.
The vulnerability was thought only to affect IE7 when first discovered, and was being exploited only by limited numbers of targeted trojans. Since then, attacks via the vulnerability have been shown to work on a wide range of Windows and IE variants, and have been widely seeded to both malicious websites and legitimate sites that have been compromised to display malicious content.
A blog post issued by Microsoft on Saturday claimed a 50% rise in attacks spotted in the previous 24 hours, with as many as 0.2% of all web users exposed to the threat. The same day, Trend Micro researchers reckoned that some 6,000 web pages were playing host to exploits targeting the vulnerability. Numbers are thought to have climbed rapidly since then.
Technical details of the vulnerability, including affected systems and possible workarounds, are in the updated advisory from Microsoft, here, or in vulnerability reporting systems at Secunia, US-CERT and Sophos. More coverage is in blog posts from F-Secure, Sophos here and here, from SANS here, and in the Washington Post here.
Posted on 16 December 2008 by Virus Bulletin