Re: Link Injection Redirection Attacks - Exploiting Google Chrome Design Flaw

[Peter Watkins <peterw () tux org>]

On Tue, Jan 05, 2010 at 10:49:07AM -0800, Michal Zalewski wrote:

> > Video: http://www.secniche.org/videos/google_chrome_link_inj.html
>
> You might find it informative to review the section of BSH on URL parsing:
> http://code.google.com/p/browsersec/wiki/Part1#Uniform_Resource_Locators

Also, a considerable part of Aditya's concern seems to be the disconnect 
between what the user sees in the Status Bar and the actual link target. 
It's easy to conceal the link's URL on a page in which the attacker can embed 
Javascript (e.g., on an attacker's Web site, but not in a well-designed 
webmail system) with code like the following:

<a href="http://google.com/"; 
   onClick="this.href='http://evil.example.com/';";>Google</a>

99% of users would see google.com in the status bar, and even "visited" 
link CSS treatment suggesting the link pointed to a page they've already
seen, making the link appear more trustworthy. This simple technique seems 
to circumvent any browser settings regarding changing or hiding the status 
bar text.

(Forgive my not digging up a reference for this approach -- surely someone 
else has written about this technique already.)

-Peter

http://www.tux.org/~peterw/