TippingPoint Zero Day Initiative

Microsoft Internet Explorer Event Object Type Double-Free Vulnerability

ZDI-09-070: October 13th, 2009


Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 8653. 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 flaw exists within the copy constructor for a specific DOM object. When duplicated, more than one reference can be made of anything assigned to it's properties. When the variable/object goes out of scope, these properties will be deallocated twice. This results in a heap corruption which can lead to code execution under the context of the current user.

Vendor Response

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

Disclosure Timeline

    2009-06-23 - Vulnerability reported to vendor
    2009-10-13 - Coordinated public release of advisory


This vulnerability was discovered by: