TippingPoint Zero Day Initiative

(Pwn2Own) Microsoft Internet Explorer Uninitialized Variable Information Leak Vulnerability

ZDI-11-198: June 14th, 2011


CVSS Score

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 11255. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows remote attackers to leak information on vulnerable installations of 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 specific flaw exists within Internet Explorer that allows malicious users to leak information about the memory layout of an Internet Explorer process. When creating a new 'Option' HTML Element, the 'index' field of the object is not set to zero and can be used to leak the location of the global variable table. This can be used to defeat ASLR or to remove the need for heap spraying while exploiting a remote code execution flaw.

Vendor Response

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

Disclosure Timeline

    2011-03-09 - Vulnerability reported to vendor
    2011-06-14 - Coordinated public release of advisory


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