TippingPoint Zero Day Initiative

Microsoft Internet Explorer VML CDispScroller Remote Code Execution Vulnerability

ZDI-12-036: February 22nd, 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 12102. 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 or open a malicious file.

The flaw exists within the handling of VML element positioning. When appending a VML element to a textArea element a reference to a cDispScroller object can be improperly freed. The object is can be reused, and due to this object being freed, a later allocation can be located in this memory region. A remote attacker can exploit this vulnerability to execute arbitrary code under the context of the process.

Vendor Response

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

Disclosure Timeline

    2011-11-29 - Vulnerability reported to vendor
    2012-02-22 - Coordinated public release of advisory


This vulnerability was discovered by:
    Stephen Fewer of Harmony Security (www.harmonysecurity.com)