TippingPoint Zero Day Initiative

Internet Explorer CTagFactory Use-After-Free Remote Code Execution Vulnerability

ZDI-12-066: April 18th, 2012

CVSS Score

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 12230. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Microsoft Internet Explorer. User interaction is required to exploit this vulnerability in that the target must visit a malicious page.

The specific issue is due to the process re-using a freed CTagFactory object. This can be made to occur by creating a specially crafted t:media element and later removing it. Remote attackers can abuse this to achieve arbitrary code execution under the context of the user running the browser.

Vendor Response

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

Disclosure Timeline

    2011-12-19 - Vulnerability reported to vendor
    2012-04-18 - Coordinated public release of advisory


This vulnerability was discovered by: