[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/

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