IE zero-day exploit code goes public

Expect attacks against unpatched browsers to gain momentum, say researchers

Exploit code for the unpatched bug in Internet Explorer was published on the Web yesterday, a step security pros said earlier would be the precursor to widespread attacks.

Israeli researcher Moshe Ben Abu used a clue in a Wednesday blog post by McAfee to grab an in-the-wild exploit, strip it of its obfuscations and use it to craft a working attack module for the popular Metasploit open-source penetration framework.

"It was quite easy," said Abu in an e-mail reply to questions late yesterday, referring to the time it took him to build the Metasploit module from the exploit code he'd found. "[It took] no more than a few minutes."

Abu's exploit was added to the Metasploit tree earlier Wednesday after review by the development team, confirmed HD Moore, the creator of the framework and chief security officer for security company Rapid7. Abu has contributed 10 exploit modules to Metasploit in the last three years, added Moore.

Microsoft first warned users of the vulnerability in Internet Explorer 6 (IE6) and IE7 on Tuesday when it issued a security advisory, typically a first step in the path toward delivering a patch when exploits or attacks are public.

By Wednesday, antivirus companies were reporting that hackers were using the exploit to launch drive-by attacks from malicious sites, including the one hosting the code that Abu found.

Abu claimed that the exploit worked on fully-patched PCs running Windows Vista Service Pack 2 (SP2) and IE7, as well as machines running Windows XP SP3 and IE6 or IE7. But the attack code isn't foolproof: It works between 60% and 75% of the time, said Abu.

Moore said it was at the lower end of Abu's range. "The exploit is somewhat unreliable, as it shares traits with other use-after-free flaws such as the bug exploited in the 'Aurora' attacks," said Moore, talking about the IE6 exploit used to hack into Google's corporate network. "Based on our testing, we are seeing the exploit work best against Windows XP SP3 IE7 with rates close to ~60%, without DEP. Other platforms are less reliable right now, but it's likely just a case of tuning the parameters for each target."

Security experts consider public posting of exploit code, especially when it's added to the popular Metasploit, as a milestone that usually means attacks will grow in number as other hackers use the code.

They also have said it's a signal that Microsoft might rush out an emergency fix. "Generally, one of the indicators is if an exploit has gone public," said Andrew Storms, director of security operations at nCircle Network Security, in an interview Tuesday. "That often determines how quickly they'll patch."

Microsoft hasn't committed to a patching schedule for the IE bug, but said Tuesday one option would be to deliver an "out-of-band" update before the company's next patch day, April 13.

Until a patch is available, Microsoft has recommended that users modify access to the "iepeers.dll," disable scripting and enabling DEP (data execution prevention). Users can also upgrade Internet Explorer to IE8 , which does not contain the bug.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags zero-day exploitsMicrosoft Internet Explorer (IE)

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.
Gregg Keizer

Gregg Keizer

Computerworld (US)
Show Comments

Cool Tech

Toys for Boys

Family Friendly

Stocking Stuffer

SmartLens - Clip on Phone Camera Lens Set of 3

Learn more >

Christmas Gift Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Aysha Strobbe

Microsoft Office 365/HP Spectre x360

Microsoft Office continues to make a student’s life that little bit easier by offering reliable, easy to use, time-saving functionality, while continuing to develop new features that further enhance what is already a formidable collection of applications

Michael Hargreaves

Microsoft Office 365/Dell XPS 15 2-in-1

I’d recommend a Dell XPS 15 2-in-1 and the new Windows 10 to anyone who needs to get serious work done (before you kick back on your couch with your favourite Netflix show.)

Maryellen Rose George

Brother PT-P750W

It’s useful for office tasks as well as pragmatic labelling of equipment and storage – just don’t get too excited and label everything in sight!

Cathy Giles

Brother MFC-L8900CDW

The Brother MFC-L8900CDW is an absolute stand out. I struggle to fault it.

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?