Thanks to prasanth for keeping us up to date.
But Microsoft has chosen to ignore it.
The hole was discovered by Adam Megacz and the details posted here yesterday.
As is usual, Mr Megacz made the browser makers aware of the problem thirty days ago but, as yet, none has come up with a fix. Expect hackers vereywhere to be fiddling with this little chink in the armoured Web, just because they can.
Microsoft PR department apparently said it would not issue a patch or hotfix, but would prefer to downplay the severity of the vulnerability instead.
SecurityFocus suggested the following work-around: "Web servers behind firewalls, " said Dave Ahmad, "should be configured to reject any HTTP requests with an unrecognized "Host" header, rather than serving pages from the "default" virtual host. This can be accomplished without patches by creating a "default" virtual host with no content, and creating a name-based virtual server for each hostname which the server is intented to serve as."
News source: The Inquirer