Microsoft on Tuesday plans to release updates patching three critical Windows security vulnerabilities, two of which are already under attack.
One of the updates plugs a hole in an Internet Explorer component that handles online video. Hundreds of thousands and possibly millions of websites - mostly catering to Chinese-speaking visitors - have been hijacked so that they secretly point to servers that exploit the critical vulnerability, creating what Microsoft has called a "browse-and-get-owned" experience for the people unfortunate enough to visit them.
"Our engineering teams have been working around the clock to produce an update for the issue discussed in Security Advisory 972890 (vulnerability in the Microsoft Video ActiveX Control) and we believe that they will be able to release an update of appropriate quality for broad distribution that protects against the attacks," Microsoft's Jerry Bryant writes here.
(Microsoft has already released a temporary fix for the bug. If you haven't installed it, you should do so now).
A second update will patch a critical vulnerability in DirectShow, the same media application related to the previously-discussed security bug. As reported in May, booby-trapped QuickTime files are being used to exploit the bug in "limited active attacks," Microsoft warns.
Both vulnerabilities affect only earlier versions of Windows. The Vista and 2008 versions of the operating system, which were developed under Microsoft's Secure Development Lifecycle, are not susceptible.
Microsoft provided few details about the third critical update, except to say that it affected all versions of Windows.
The details were released under a bulletin Microsoft releases on the Thursday before its Patch Tuesday, which falls on the second Tuesday of each month. The advance notice is designed to give IT employees who administer large numbers of PCs adequate time to prepare for the updates.
Tuesday's patch batch also includes updates fixing three vulnerabilities rated "important" in its Publisher app, Internet Security and Acceleration Server, and Virtual PC and Virtual Server.
The updates may or may not require machines to be rebooted, depending on whether certain DLL files are in use when the patch is applied. ®