TippingPoint Zero Day Initiative

Apple QuickTime AVI Header nBlockAlign Heap Corruption Vulnerability

ZDI-09-006: January 21st, 2009


Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 6642. For further product information on the TippingPoint IPS:

Vulnerability Details

This vulnerability allows attackers to execute arbitrary code on vulnerable installations of Apple QuickTime. 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 the parsing of AVI files. When the AVI header contains a malformed nBlockAlign value in the _WAVEFORMATEX structure, a heap overflow may occur which can be leveraged to execute arbitrary code under the context of the current user.

Vendor Response

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

Disclosure Timeline

    2008-10-15 - Vulnerability reported to vendor
    2009-01-21 - Coordinated public release of advisory


This vulnerability was discovered by: