Vulnerability in Microsoft XML HTTP Request Handling

Notification Type: Internet Security Systems Protection Alert
Notification Date: November 4, 2006
Notification Version: 1.3
Name: Vulnerability in Microsoft XML HTTP Request Handling
Public disclosure/
In the wild date:
November 3, 2006

ISS X-Force was the first research group to discover active exploitation of an undislosed vulnerability in Microsoft’s XML HTTP request handling. 

Current exploitation of this vulnerability through Internet Explorer.  Specifically, these exploits target Internet Explorer through a vulnerable ActiveX control.  Successful exploitation of this vulnerability may result in remote code execution.

All ISS IPS/IDS products and host products had pre-emptive protection against this threat through heuristic Javascript/Shellcode exploit detection signatures and through Buffer Overflow Exploit Prevention (BOEP).  In addition to this pre-emptive protection, ISS has provided a third IPS/IDS signature to prevent this specific vulnerability from being exploited.

Our web-filtering technology is automatically updated to protect against malicious sites that attempt to host this kind of malicious material.  Every customer using our filtering technology or database of URL's was protected within moments of this discovery in early Nov.


ISS Coverage


Content Version

Network Sensor 7.0
Proventia A
Proventia IPS (G/GX) prior to Firmware Version 1.2
Server Sensor 7.0


Proventia IPS (G/GX) Firmware Version 1.2 or
Proventia M
Proventia Server (Linux)


Proventia Server (Windows)


Proventia Desktop


RealSecure Desktop 7.0


BlackICE PC Protection 3.6


Proventia Web

early Nov update for malicious websites

Propagation Techniques

ISS Protection

web browsing, email link, etc.


Buffer Overflow Exploit Preventiion (BOEP)

Web filtering

Mar 24, 2006
Mar 28, 2006
Nov 7, 2006

May 10, 2005

 Nov 2 2006

Detailed Description

Business Impact: An attacker may host a maliciously crafted HTML document on a website and entice the victim to click on a link, which will load the document in their browser. Once the document is loaded, the attacker will be able to execute arbitrary code on the victim’s machine with the permissions of the victim user. This could lead to loss of confidential information, disruption of business, or further compromise of internal systems and networks.
CVSS: Base Score:  8.0
  Access Vector:  Remote
Access Complexity:  High
Authentication:  Not Required
Confidentiality Impact:  Complete
Integrity Impact:  Complete
Availability Impact:  Complete
Impact Bias:  Normal
Adjusted Temporal Score:  7.6
  Exploitability:  Functional
Remediation Level:  Unavailable
Report Confidence:  Confirmed
Affected Products: Microsoft XML Core Services 4.0 when installed on Windows 2000 Service Pack 4

Microsoft XML Core Services 4.0 when installed on Microsoft Windows XP
Service Pack 2

Microsoft XML Core Services 4.0 when installed on Microsoft Windows Server 2003 and Microsoft Windows Server 2003 Service Pack 1
Technical Description: This vulnerability resides in some of the core XML engines within Microsoft Windows.  It is the result of the engine’s inability to properly handle improper arguments passed to one of the methods associated with the XML request object.

This improper handling results in memory corruption and ultimately may result in remote code execution.

While many third party applications may make use of the vulnerable request object, X-Force feels that there are such specific requirements to trigger the vulnerable condition, that this is most likely only exploitable by instantiating the vulnerable object within a web browser.


X-Force Database

Revision History

Version 1.0 November 4, 2006 - Initial alert release

Version 1.1 November 6, 2006 - Added confirmation that buffer overflow exploit prevention stopped these exploits

Version 1.2 November 7, 2006 - Changed affected versions to focus on vulnerable component and added additional coverage information

Verison 1.3 November 8, 2006 - Added content filtering information and converted to new alert format.

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