Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to bypass security restrictions. Updates are available.
Description
Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to bypass security restrictions.
The vulnerability is due to improper handling of SSL version 3 (SSLv3) and Transport Layer Security (TLS) session version negotiation by the affected software. An unauthenticated, remote attacker who has successfully intercepted web traffic handshakes could exploit the vulnerability by injecting crafted content into an SSL/TLS session. If successful, the attacker could bypass security restrictions in SSLv3 by downgrading to SSLv2.
Microsoft confirmed the vulnerability in a security bulletin and released software updates.
Warning Indicators
The following Microsoft products are vulnerable:
Windows Vista SP2
Windows Vista x64 Edition SP2
Windows Server 2008 for 32-bit Systems SP2
Windows Server 2008 for x64-based Systems SP2
Windows Server 2008 for Itanium-based Systems SP2
Windows 7 for 32-bit Systems SP1 and prior
Windows 7 for x64-based Systems SP1 and prior
Windows Server 2008 R2 for x64-based Systems SP1 and prior
Windows Server 2008 R2 for Itanium-based Systems SP1 and prior
Windows 8 for 32-bit Systems
Windows 8 for x64-based Systems
Windows Server 2012
Windows RT
IntelliShield Analysis
To exploit this vulnerability, an attacker must intercept an SSL/TLS session, possibly by performing a man-in-the-middle attack against the targeted system. This requirement decreases the likelihood of a successful exploit.
Microsoft has corrected this vulnerability by modifying the way the Windows SSL provider component handles encrypted network packets.
The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the January 2013 security bulletin release. This Cisco bulletin, which assists administrators in identifying or mitigating these vulnerabilities using Cisco devices, is available at the following link: Cisco Applied Mitigation Bulletin: Microsoft Security Bulletin Release for January 2013
Vendor Announcements
Microsoft has released a security bulletin at the following link: MS13-006
Impact
An unauthenticated, remote attacker could exploit this vulnerability to downgrade an SSLv3 or TLS connection to SSLv2, which could weaken security on an affected system.
Technical Information
The vulnerability is due to improper handling of SSLv3 and TLS session version negotiation by the affected software while encrypting network traffic.
An unauthenticated, remote attacker who has successfully intercepted web traffic handshakes could exploit the vulnerability by injecting crafted content into an SSL/TLS session. If successful, the attacker could bypass security restrictions in SSLv3 by downgrading to SSLv2.
Safeguards
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators may consider disabling SSLv2 in Internet Explorer and Internet Information Services (IIS).
Administrators are advised to monitor affected systems.
Patches/Software
Microsoft customers can obtain updates directly by using the links in the security bulletin. These updates are also distributed by Windows automatic update features and available on the Microsoft Update service. Microsoft Windows Server Update Services (WSUS), Systems Management Server, and System Center Configuration Manager can assist administrators in deploying software updates.
The security vulnerability applies to the following combinations of products.
Primary Products:
Microsoft, Inc.
Windows 7
for 32-bit systems SP1 | for x64-based systems Base, SP1
Microsoft, Inc.
Windows 8
for 32-bit systems Base | for x64-based systems Base
Microsoft, Inc.
Windows RT
Original Release Base
Microsoft, Inc.
Windows Server 2008
Datacenter Edition SP2 | Datacenter Edition, 64-bit SP2 | Enterprise Edition SP2 | Enterprise Edition, 64-bit SP2 | Essential Business Server Premium SP2 | Essential Business Server Premium, 64-bit SP2 | Essential Business Server Standard SP2 | Itanium-Based Systems Edition SP2 | Standard Edition SP2 | Standard Edition, 64-bit SP2 | Web Server SP2 | Web Server, 64-bit SP2
Microsoft, Inc.
Windows Server 2008 R2
Itanium-Based Systems Edition Base, SP1 | x64-Based Systems Edition Base, SP1
Microsoft, Inc.
Windows Server 2012
Original Release Base
Microsoft, Inc.
Windows Vista
Business SP2 | Business x64 Edition SP2 | Enterprise SP2 | Enterprise x64 Edition SP2 | Home Basic SP2 | Home Basic x64 Edition SP2 | Home Premium SP2 | Home Premium x64 Edition SP2 | Ultimate SP2 | Ultimate x64 Edition SP2
Associated Products:
N/A
Alerts and bulletins on the Cisco Security Intelligence Operations Portal are highlighted by analysts in the
Cisco Threat Operations Center and represent a subset of the comprehensive content that is available through Cisco Security IntelliShield Alert Manager Service.
This customizable threat and vulnerability alert service provides security staff with access to timely, accurate, and credible information about threats and vulnerabilities that may affect their environment. Cisco is pleased to offer a free trial of the service.
To register for full access, please visit the IntelliShield trial registration page.
LEGAL DISCLAIMER The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
