Check Point Advisories

Microsoft XML Signature HMAC Truncation Bypass (MS10-041; CVE-2009-0217)

Vulnerability
Protection

Check Point Reference:	CPAI-2010-201
Date Published:	8 Jun 2010
Severity:	High
Last Updated:	Thursday 16 April, 2015
Source:
Industry Reference:	CVE-2009-0217
Protection Provided by:	Security Gateway R81, R80, R77, R75, R71, R70, R65
Who is Vulnerable?
Vulnerability Description	The Microsoft .NET Framework is a component of the Microsoft Windows operating system that enables building and running software applications and Web services. A tampering vulnerability exists in the Microsoft .NET Framework that could allow an attacker to tamper with signed XML content without being detected. The vulnerability is caused by the way that the W3C XML Signature Syntax and Processing (XMLDsig) recommendation has been implemented in the Microsoft .NET Framework. An attacker could exploit this issue by sending a specially crafted XML content to a vulnerable system. Successful exploitation of this vulnerability could allow an attacker to bypass certain cryptographic signatures and as a result, tamper with signed XML content without the receiver detecting the changes.

Protection Overview

This protection will detect and block the transferring of malformed XML files over HTTP.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R80 / R77 / R75 / R71 / R70 / R65

In the IPS tab, click Protections and find the Microsoft XML Signature HMAC Truncation Bypass (MS10-041) protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: Content Protection Violation.
Attack Information: Microsoft XML signature HMAC truncation bypass (MS10-041)