Another Denial of Service Bug Found in Firefox 2

An anonymous reader writes "A second security flaw that could cause the new Firefox 2 browser to crash has been publicly disclosed. The vulnerability lies in the way the open-source browser handles JavaScript code. Viewing a rigged Web page will cause the browser to exit, a representative for Mozilla, the publisher of the software, said Wednesday. Contrary to claims on security mailing lists, the bug cannot be exploited to run arbitrary code on a PC running Firefox 2, the representative said. This flaw in the JavaScript Range object is different than the denial-of-service vulnerability in Firefox 2 that was confirmed by Mozilla last week. That bug is related to a more serious security hole, which was fixed in earlier versions of Firefox, the organization has said. The two 'crashers' are the only publicly released vulnerabilities that have been confirmed by Mozilla in the week since Firefox 2 was launched. The issues are only minor, the organization has said."

Comments

Old times

[managementboy]

It used to be that if one an application crashed and it was called just that: it crashed. Today its a DOS attack! Imagine how many DOS my old Windows 3.11 had... come to think of it, it only had one DOS.

We present "DOS reloaded"!

Re:Old times

[cperciva]

It used to be that if one an application crashed and it was called just that: it crashed. Today its a DOS attack!

Not necessarily. Application-crashing bugs are Denial of Service bugs if they can be triggered remotely.

There's a fundamental difference between "I can make my copy of FireFox crash" and "I can make your copy of FireFox crash".

Re:Old times

[jesser]

More to the point, there's a fundamental difference between "I can make your copy of Firefox crash when you visit my site" and "I can make your copy of Apache crash".

Crash bugs in client software such as web browsers are "crashes", not "DoS vulnerabilities".

Re:LOL IE Users!

[Mikachu]

Except let's see how long it takes for the Firefox team to patch up these flaws as opposed to IE.

There's a browser safer than Firefox...

[Giorgio Maone]

... it is Firefox with NoScript :)

I wrote this Firefox add-on just after one of these disclosures, because the majority of the browser vulnerabilities was JavaScript related, and the suggested work-around was always "turn off JavaScript".

Disabling JavaScript as a whole seemed quite an impractical advice to me in this AJAXified Web 2.0: I thought that maintaining a white-list of trusted sites allowed to run JavaScript and keeping all the unknown web content "static" until I decided otherwise was a still safe but more convenient approach.

Since then I've been browsing the web with my shields up (NoScript can block also Java, Flash and other plugins), but I allow on the fly with one click, either temporarily or permanently, those sites which I trust and which do need dynamic client side technologies to work properly. To my surprise in 1 year and half I found few sites belonging to this category, because most places I usually browse are well designed enough to work with plain XHTML/CSS and nothing else (like Slashdot itself).

Notice: Firefox is a very safe browser because its vulnerabilities gets patched very quickly, once they're found by developers. I'm a Firefox contributor myself, and I'm very proud of the quality of the Mozilla developers community. NoScript, though, provides some extra protection even against those JavaScript/Java related vulnerabilities which have not been found yet...

Third d.o.s. attack affects ALL BROWSERS!

[suv4x4]

Immediately stop using Internet if you're using one of those browsers:

IE
Firefox
Safari
Konqueror .. ..

A new denial of service attack was discovered floating in the cyberspace, that can render any browser inoperable, and it has to be forcefully crashed and reopened. The signature of the exploit was reported to be:

while(true) alert('Hahaha, suckers!');

People are advised to immediately move to Lynx: the only browser known to be immune to this attack.