Microsoft Windows Protection Engine Remote Heap Overflow

Notification Type: IBM Internet Security Systems Protection Advisory
Notification Date: Feb 13, 2007
Notification Version: 1.1

Microsoft Windows Protection Engine Remote Heap Overflow

Public disclosure/
In the wild date:
Feb 13, 2007 (vuln)
CVE: CVE-2006-5270
Description: IBM X-Force has discovered a remote code execution vulnerability in Microsoft Windows Protection, a default component of Windows Live

OneCare, Antigen, Forefront Security, and Windows Defender, including Windows Defender for Vista.

Discoverers/Researchers: Alex Wheeler and Neel Mehta, IBM X-Force



ISS Coverage

Product Content Version
Proventia Desktop
Propagation Techniques ISS Protection Available
email, web 


* name subject to change 

 Jan 10, 2007

Detailed Description

Business Impact: Compromise of machines using affected versions of the Microsoft Protection Engine library may lead to exposure of confidential information, loss of productivity, and further compromise. Successful exploitation grants an attacker remote, system-level privileges. 
CVSS: Base Score: 10.0
  Access Vector: Remote 
Access Complexity: Low
Authentication: Not Required 
Confidentiality Impact: Complete 
Integrity Impact: Complete 
Availability Impact: Complete 
Impact Bias: Normal
Adjusted Temporal Score: 7.4
  Exploitability: Unproven 
Remediation Level: Official Fix 
Report Confidence: Confirmed 
Affected Products:

Affected Software:

  • Windows Live OneCare
  • Microsoft Antigen for Exchange Server 9.x
  • Microsoft Antigen for SMTP Server 9.x
  • Microsoft Windows Defender
  • Microsoft Windows Defender x64 Edition
  • Microsoft Windows Defender in Windows Vista
  • Microsoft Forefront Security for Exchange Server 10
  • Microsoft Forefront Security for SharePoint Server 10

Affected Components:

  • Microsoft Malware Protection Engine 
Technical Description:

This vulnerability is in the Microsoft Windows Protection Engine, a shared library designed to parse data streams for malware. 

By sending a specially crafted PDF file, an attacker can trigger a heap overflow resulting in remote code execution. This file may be sent over common protocols, such as SMTP, HTTP, FTP, etc.  In many cases, this vulnerability may be triggered without user interaction.

This vulnerability exists because an arbitrary integer from a PDF file is used in a memory allocation calculation without proper bounds checking. As a result, an attacker may provide a large integer value creating an integer overflow in the calculation. This attack causes a heap overflow with arbitrary file data. There are several structures on the heap that an attacker may abuse to obtain remote code execution.

Remediation: Microsoft has provided patches for all affected products.  See References for details. 



Revision History

1.0 Initial advisory.
1.1 Revised CVSS score.

* According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES "AS IS" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.
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