TippingPoint Zero Day Initiative

Microsoft Internet Explorer Baseline Tag Rendering Remote Code Execution Vulnerability

ZDI-10-012: January 21st, 2010


CVSS Score

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 9429. 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 an attacker must coerce a victim to visit a malicious page.

The specific flaw exists due to the application rendering intertwined strike and center tags containing an element that manipulates the font baseline such as 'sub' or 'sup'. When this element pointer is removed the application will later dereference it even though it has been freed. Successful exploitation can lead to arbitrary code execution under the context of the currently logged in user.

Vendor Response

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

Disclosure Timeline

    2009-07-16 - Vulnerability reported to vendor
    2010-01-21 - Coordinated public release of advisory


This vulnerability was discovered by:
    Sam Thomas of eshu.co.uk