TippingPoint Zero Day Initiative

Apple Webkit Error Message Mutation Remote Code Execution Vulnerability

ZDI-11-095: March 2nd, 2011


CVSS Score

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 10890. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Safari's 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 methodology the application takes to inform a user about an error while parsing a malformed document. When displaying the error message, the application will append the message to the current instance of the DOM tree causing another element to be removed which will lead to the styles being recalculated. When the styles are recalculated the application will access the initially freed element which can lead to code execution under the context of the application.

Vendor Response

Apple has issued an update to correct this vulnerability. More details can be found at:

Disclosure Timeline

    2010-10-18 - Vulnerability reported to vendor
    2011-03-02 - Coordinated public release of advisory


This vulnerability was discovered by:
    wushi of team509