[MajorSecurity Advisory #64]Apple Safari 4.0.4 Denial of Service

[david@xxxxxxxxxxxxxxxxxx]

[MajorSecurity Advisory #64]Apple Safari 4.0.4 Denial of Service

Details
============
Product: Apple Safari Webbrowser
Security-Risk: low
Remote-Exploit: yes
Vendor-URL: http://www.apple.com/safari/
Vendor-Status: informed
Advisory-Status: published on 02-02-2010

Credits
============
Discovered by: David Vieira-Kurz
http://www.majorsecurity.info

Affected Products:
============
Apple Safari browser 4.0.4 an prior

Original Advisory:
============
http://www.majorsecurity.info/index_2.php?adv=major_rls64

Introduction
============
The Apple Safari browser is a webbrowser based on the WebKit Engine.

More Details
============
A remotely exploitable vulnerability has been found in the JavaScript Engine of 
the Apple Safari Browser(based on Webkit Engine).
In detail, the following flaw was determined:
The Apple Safari browser is prone to a denial of service vulnerability when 
parsing certain HTML content.
This is possible due to a failure in handling exceptional conditions. This 
issue is caused by a memory corruption error when handling javascript elements, 
which could be exploited by remote attackers to crash the browser by tricking a 
user into visiting a specially crafted web page.
This issue can NOT be lead to remote code execution, so that the potential 
security risk is rated low.

The exploit has been tested on Windows Vista SP2 with Safari 4.0.4 using 
following useragent:
Mozilla/5.0 (Windows; U; Windows NT 6.0; de-DE) AppleWebKit/531.21.8 (KHTML, 
like Gecko) Version/4.0.4 Safari/531.21.10

Proof of Concept:
============
<script>
var overloadtag = "<marquee>";
for(x=1;x<=9999999999;x++){
document.write(overloadtag);
}
</script>

MajorSecurity
================
MajorSecurity is a German penetrationtesting and security research company 
which focuses
on web application security. We offer professional penetrationtestings, 
security audits,
source code reviews and reliable proof of concepts.
You will find more Information about MajorSecurity at
http://www.majorsecurity.info/

Unaltered electronic reproduction of this advisory is permitted. For all other 
reproduction or publication, in printing or otherwise, contact 
office@xxxxxxxxxxxxxxxxxx for permission.
Use of the advisory constitutes acceptance for use in an "as is" condition. All 
warranties are excluded. In no event shall majorsecurity and David Vieira-Kurz 
IT Security Services be liable for any damages whatsoever including direct, 
indirect, incidental, consequential, loss of business profits or special 
damages, even if majorsecurity has been advised of the possibility of such 
damages.Copyright 2010 MajorSecurity and David Vieira-Kurz IT Security 
Services. All rights reserved. Terms of use apply.