TippingPoint Zero Day Initiative

Microsoft Internet Explorer writing-mode Memory Corruption Vulnerability

ZDI-09-071: 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 8654. 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 in that a user must visit a malicious web page.

The specific flaw exists in the parsing of CSS style information. When a writing-mode style is used with a specific combination of HTML tags, memory corruption occurs. Exploitation of this vulnerability will lead to remote system compromise under the credentials 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

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


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