Microsoft yesterday said it is testing a patch for a critical vulnerability in Internet Explorer (IE), but stopped short of promising to deliver an emergency fix before the next scheduled Patch Tuesday.

"We have seen speculation that Microsoft might release an update for this issue out-of-band," said Jerry Bryant, a senior manager with the Microsoft Security Response Center (MSRC), referring to the term the company uses for a rush fix. "I can tell you that we are working hard to produce an update which is now in testing."

Microsoft first warned users of the vulnerability in IE6 and IE7 last Tuesday when it said hackers were exploiting the bug. The next day, Israeli security researcher Moshe Ben Abu grabbed the attack code from a site that had been using it to conduct "drive-by" attacks, then crafted a public exploit, which he published to the popular Metasploit penetration testing framework.

Even before Abu posted his exploit, security experts had said they expected Microsoft to ship an out-of-band update if attack code went public.

Full story: Computerworld