TippingPoint Zero Day Initiative

Microsoft Internet Explorer CSS Class Ordering Memory Corruption Vulnerability

ZDI-06-027: August 8th, 2006


Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 4605. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows 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 vulnerability exists due to improper handling of CSS class values. Accessing a specially crafted CSS element via document.getElementByID causes a memory corruption eventually leading to code execution.

Vendor Response

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

Disclosure Timeline

    2006-06-14 - Vulnerability reported to vendor
    2006-08-08 - Coordinated public release of advisory


This vulnerability was discovered by:
    Sam Thomas