HScan Redux

Fri, 23 Feb 2007 12:28:43 GMT

Inspired by Michal Zalewski's recent Firefox bug hunt, I decided to give it a go and see what I can come up with. We all know how vulnerable Firefox and other browsers are. This is the reason why I am not particularly interested in finding specific browser bugs.

This vulnerability is not a reworked version of Jeremiah Grossman history hack. It is completely different and it should be treated as a new issue. The peculiar thing about this vulnerability is that it tells you which URLs you have attended during the current browser session (the last time you opened your browser). I am not sure how useful this really is.

Keep in mind that attackers can abuse this vulnerability to extract valuable information about your browsing habits. Attackers can also use this hack to precisely detect whether you are logged into your router management interface, for example. This hack can also be used to detect your router type and version as well. Based on this information, attackers might be able to compromise the integrity of your network.

The POC is located here. If all checks show up as NOT visited, then visit one of the listed URLs and retest again.

Archived Comments

.mario

This is a very interesting approach of history stealing! I didn't know about the about:cache-entry directive. I guess i will spend some time the next days to check what other about: directives are available and maybe exploitable... Great find!

pdp

.mario about:cache is actually a protocol to access Firefox internal cache information. There are a few other about: directives. about:mozilla is fun.

duk

Firefox 2.0.0.2 is also vulnerable

.mario

What about XHRing the URL about:cache?device=disk and parsing out all URLs from the response body via regex? Then you'd have a complete history theft - guess i have to test that tomorrow. BTW, it's .mario with an o...

pdp

sorry man, fixed it. I am almost certain that you cannot read about:cache with XMLHttpRequest.

.mario

Thanx ;) I did a little quick test and from what i acn say it is hard to impossible. I will give it a deeper look tomorrow. I used it on a jquery featured site trying this:

$.get('about:cache?device=disk', function(response){alert(response);});

-am

Works on FF 1.5.0.9/WinXP. Good catch :)

pdp

It works on Mac OS 10.4.8 Firefox 2.0.0.1 too.

dusoft

Does not work for Firefox 2.0.0.1 under Linux

Adriaan

Indeed. Does not work under gentoo linux, 2.0.0.1.

Jordan

Doesn't work for me, OS X, FF 2.0.0.1 but it's probably SafeCache or SafeHistory blocking it. http://safecache.com/ http://safehistory.com/

MustLive

Don't work in my Mozilla 1.7.7 :P (and in old version of Firefox). Old version browsers rulez! :-) Want to save your history - use old school browsers.

mozzio

No surprise, any version of the Mozilla browsers with NoScript installed is immune. http://noscript.net