ZDI-11-135: (Pwn2Own) WebKit WBR Tag Removal Remote Code Execution Vulnerability

http://www.zerodayinitiative.com/advisories/ZDI-11-135

April 14, 2011

-- CVE ID:
CVE-2011-1344

-- CVSS:
9, (AV:N/AC:L/Au:N/C:P/I:P/A:C)

-- Affected Vendors:
WebKit

-- Affected Products:
WebKit WebKit

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 10970. 
For further product information on the TippingPoint IPS, visit:

    http://www.tippingpoint.com

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Webkit. User interaction is required to
exploit this vulnerability in that the target must visit a malicious
page or open a malicious file.

The specific flaw exists within the way the Webkit library handles WBR
tags on a webpage. By adding children to a WBR tag and then consequently
removing the tag through, for example, a 'removeChild' call it is
possible to create a dangling pointer that can result in remote code
execution under the context of the current user.

-- Vendor Response:
Google patch on March 12, 2011:
http://googlechromereleases.blogspot.com/2011/03/stable-and-beta-channel-updates.html

Apple patch on April 14, 2011:
http://support.apple.com/kb/HT4606
http://support.apple.com/kb/HT4607
http://support.apple.com/kb/HT4596

-- Disclosure Timeline:
2011-03-31 - Vulnerability reported to vendor
2011-04-14 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by:
    * Vupen Security

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