Home Page | Skip to Navigation | Skip to Content | Skip to Search | Skip to Footer

Preemptive Protection against Microsoft CryptoAPI Null Truncation in X.509 Common Name Vulnerability (MS09-056)

Subscribe

Check Point Reference: CPAI-2009-226
Date Published:
Preemptive Since:
Severity:
Last Updated:
Source: Microsoft Security Bulletin MS09-056
Industry Reference(s): CVE-2009-2510
Protection Provided by: Security Gateway
  • R70
VPN-1
  • NGX R65
VSX
  • NGX R65
IPS-1
  • IPS-1
  • IPS-1 NGX R65
Who is Vulnerable?
Microsoft Windows 2000 SP4
Windows XP SP2
Windows XP SP3
Windows XP Professional x64 Edition SP2
Windows Server 2003 SP2
Windows Server 2003 x64 Edition SP2
Windows Server 2003 with SP2 (Itanium)
Windows Vista
Windows Vista SP1
Windows Vista SP2
Windows Vista x64 Edition
Windows Vista x64 Edition SP1
Windows Vista x64 Edition SP2
Windows Server 2008 for 32-bit Systems
Windows Server 2008 for 32-bit Systems SP2
Windows Server 2008 for x64-based Systems
Windows Server 2008 for x64-based Systems SP2
Windows Server 2008 (Itanium)
Windows Server 2008 (Itanium) SP2
Windows 7 for 32-bit Systems
Windows 7 for x64-based Systems
Windows Server 2008 R2 for x64-based Systems
Windows Server 2008 R2 (Itanium)
Vulnerability Description
A spoofing vulnerability has been reported in the Microsoft Windows CryptoAPI component when parsing ASN.1 information from X.509 certificates. The CryptoAPI provide services that enable application developers to add encryption/decryption of data, authentication using digital certificates, and encoding to and decoding from Abstract Syntax Notation One (ASN.1) to their Windows-based applications. A remote attacker who successfully exploited this vulnerability could impersonate another user or system.
Update/Patch Available
Apply patches:
Microsoft Security Bulletin MS09-056
Vulnerability Details
The vulnerability is due to an error in the Windows CryptoAPI that incorrectly parses a null terminator as the end of any values identified by an Object Identifier (OID). This causes the CryptoAPI to only parse part of the actual value. When this partial value has meaning to the end user, this may lead to a situation where an attacker could impersonate another user or system.

Protection Overview
This protection will detect and block NULL prefix found in SSL certificates.

Users of R70 and R65 are protected against this vulnerability if the protection for blocking the Firefox Common Name security bypass in the Protection section of CPAI-2009-129 has been applied.

To configure the defense, select your product from the list below and follow the related protection steps.

Security Gateway R70

How Can I Protect My Network?
1. In the IPS tab, click Protections > By Protocol > Web Intelligence > HTTP Client Protections.
2. In the right pane, double-click the SSL NULL Termination Certificate Validation Security Bypass protection.
3. In the Protection Details window, click on Edit. Choose the protection's Action (Override IPS Policy with: Prevent/Detect), and apply Additional Settings.
4. Install policy on all modules.

How Do I Know if My Network is Under Attack?
SmartView Tracker will log the following entries:

Attack Name: Invalid SSL Packet
Attack Information: SSL NULL termination certificate validation security bypass

VPN-1 NGX R65

How Can I Protect My Network?
1. In the SmartDefense tab, click Web Intelligence > HTTP Client Protections.
2. Select the following protection:

SSL NULL Termination Certificate Validation Security Bypass

3. In the configuration pane, under Settings > Mode, check Active.
4. Install policy on all modules.

How Do I Know if My Network is Under Attack?
SmartView Tracker will log the following entries:

Attack Name: Invalid SSL Packet
Attack Information: SSL NULL termination certificate validation security bypass

VPN-1 VSX NGX R65

How Can I Protect My Network?
1. In the SmartDefense tab, click Web Intelligence > HTTP Client Protections.
2. Select the following protection:

SSL NULL Termination Certificate Validation Security Bypass

3. In the configuration pane, under Settings > Mode, check Active.
4. Install policy on all modules.

How Do I Know if My Network is Under Attack?
SmartView Tracker will log the following entries:

Attack Name: Invalid SSL Packet
Attack Information: SSL NULL termination certificate validation security bypass

IPS-1 & IPS-1 NGX R65

How Can I Protect My Network?

1. In the IPS-1 Policy Manager, click on the Protection tab.
2. In the Protection tree, click Network Security > SSL, and select the SSLv3/TLS Server Hello protection group.
3. Click SSL Certificate Man-In-The-Middle Attack (IPS-1 NGX R65 only).
4. In the configuration pane, under Settings, check Active.
5. Click on Install Policy.

How Do I Know if My Network is Under Attack?

Upon attack, the following entries will be logged:

Alert Name: SSLv3/TLS Server Hello
Description: SSL Certificate Man-In-The-Middle Attack