Mozilla Privacy Bug

Saturday September 14th, 2002

Yesterday, ZDNet UK News reported that Mozilla has a privacy flaw involving HTTP referers. The flaw can be exploited using the onUnload JavaScript handler, which is triggered when a visitor leaves a page (for example, by clicking a link or using a bookmark). The problem is that the referer Mozilla sends is the URL of the page that the visitor is going to, not the page that he or she is exiting. This means that a site can discover where you are heading when you leave.

The security bug is present in the latest versions of Mozilla (including 1.0.1, 1.1 and 1.2 Alpha) as well as some Mozilla-based browsers, such as Netscape 6.x, Netscape 7.0, Galeon 1.2.x and Chimera 0.5. At the time of writing, no fix is available. A workaround is to disable JavaScript (Edit > Preferences > Advanced > Scripts & Plugins).

A demonstration of the exploit has been created by security researcher Sven Neuhaus, who posted details of the vulnerability to Bugtraq on Wednesday.

The bug was filed in Bugzilla as bug 145579 on Sunday 19th May, with the more serious onUnload behaviour found on Friday 7th June. The report is currently marked as "Security-Sensitive" and access to it is restricted in line with the Mozilla Security Bugs Policy.

UPDATE! Bug 145579 has now been made public.

ANOTHER UPDATE! A fix has been checked in to the trunk. A patch for the 1.0 branch will follow shortly.

YET ANOTHER UPDATE! A patch has now been checked in to the 1.0 branch.

#54 Re: Re: Re: Re: Re: Track Record

by Dobbins

Wednesday September 18th, 2002 9:07 AM

You are replying to this message

You don't understand the "Black hat" mentality. The number of users dosen't matter. Putting the exploit to use dosen't matter. The "fame", the admiration of other hackers is all that matters.

Finding yet another hole in MEIE is old hat. Finding an exploit in Mozilla is new territory. It will bring more recognition among other hackers than finding yet another exploit in MSIE. It's worth more in the hacker community.

The real problems start after the "black hat" feeds his ego by releasing the exploit on a hacker site. That is when the "script kiddies" pick it up and start using the exploit.

So far the "black hats" have scored ZERO exploits in Mozilla. That makes it a very tempting target. Being the first "black hat" to find a hole in Mozilla will gain a lot of recognition among hackers.