Check Point Advisories

Microsoft .Net Form Authentication Insecure Redirect (MS11-100; CVE-2011-3415)

Vulnerability
Protection

Check Point Reference:	CPAI-2011-602
Date Published:	30 Dec 2011
Severity:	High
Last Updated:	Sunday 05 October, 2014
Source:
Industry Reference:	CVE-2011-3415
Protection Provided by:	Security Gateway R81, R80, R77, R75, R71, R70
Who is Vulnerable?
Vulnerability Description	A spoofing vulnerability has been reported in Microsoft .NET Framework. The vulnerability is due to an error in the way .NET Framework verifies return URLs during the forms authentication process. A remote attacker may exploit this vulnerability by enticing users to open a malicious link. Successful exploitation would allow an attacker to redirect users to a website of the attacker's choosing. The attacker may then perform a phishing attack to gain information that was not meant to be disclosed.

Protection Overview

IPS will detect and block malicious URLs.

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

In the IPS tab, click Protections and find the Microsoft .Net Form Authentication Insecure Redirect (MS11-100) 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: Web Server Enforcement Violation.
Attack Information: Microsoft .Net Form Authentication insecure redirect (MS11-100)