I have identified a second critical 0day vulnerability in Firebug which also affects the updated Firebug v1.0.3. The scope is the same, read/write/execute files. http://larholm.com/2007/04/06/more-0day-in-firebug/ There's a detailed walkthrough at the above, including a simplistic POC that verifies whether script was injected into the browser Chrome.
From there any practical exploit would be similar to all of the older
Firefox browser Chrome exploits. Joe Hewitt has already responded to the above and my previous post (http://larholm.com/2007/04/06/0day-vulnerability-in-firebug/), stating that an updated version of Firebug (1.0.4) should be released now. Updates are available and should trickle out to Firebug users through Mozilla's automated update system within the next few days. If you can't wait for that then go to Tools, Add-ons and click "Find Updates". The updated version of Firebug should also prevent any closely related vulnerabilities as Joe has updated his domplate constructors to forcefully escape all strings before they are inserted into the console HTML. Cheers Thor Larholm On 4/4/07, pdp (architect) <pdp.gnucitizen@xxxxxxxxxxxxxx> wrote:
http://www.gnucitizen.org/blog/firebug-goes-evil There is critical vulnerability in Firefox/Firebug which allows attackers to inject code inside the browser chrome. This can lead to a lot of problems. Theoretically everything is possible, from modifying the user file system to launching processes, installing ROOTKITs, you name it. I recommend to disable Firebug for now until the issue is fixed. The issues is a bit critical since Firebug is one of the most popular extensions for Firefox. Given the fact that a lot of the Firefox users are geeks, the chances to have Firebug installed in a random Firefox client are quite high. I wrote two POC to demonstrate the issue. You can find them from the page on the top of this message. The first POC runs calc.exe and cmd.exe on windows systems. The second POC does a count down from 10 to 0 and executes calc.exe to prove that automatic execution is possible. -- pdp (architect) | petko d. petkov http://www.gnucitizen.org
