Michal Zalewski has noted some interested security bugs with Safari, Firefox and WebKit-based browsers.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/91167/safarifirefox-zalewski.txt
Source: https://packetstormsecurity.com/files/91167/Safari-SOP-Bypass-Firefox-Address-Bar-Spoofing.html