Microsoft has released an additional security advisory and software updates to address the TrueType font parsing remote code execution vulnerability.
Description
Microsoft Windows, Office, Silverlight, and Lync contain a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on a targeted system.
The vulnerability exists because of improper processing of TrueType fonts by the affected software. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious Microsoft Word document (.doc). If successful, the attacker could execute arbitrary code on the system with elevated privileges.
Microsoft has confirmed the vulnerability in a security bulletin and released software updates.
Warning Indicators
The following Microsoft systems are vulnerable:
Silverlight 4
Silverlight 5
Office 2003 SP3 and prior
Office 2007 SP3 and prior
Office (32-bit editions) 2010 SP1 and prior
Office (64-bit editions) 2010 SP1 and prior
Lync 2010 32-bit and 64-bit
Lync 2010 Attendee
Windows XP SP3 and prior
Windows XP Professional x64 Edition SP2 and prior
Windows Server 2003 SP2 and prior
Windows Server 2003 x64 Edition SP2 and prior
Windows Server 2003 for Itanium-based Systems SP2 and prior
Windows Vista SP2 and prior
Windows Vista x64 Edition SP2 and prior
Windows Server 2008 for 32-bit Systems SP2 and prior
Windows Server 2008 for x64-based Systems SP2 and prior
Windows Server 2008 for Itanium-based Systems SP2 and prior
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
IntelliShield Analysis
Microsoft has released a Fix-It solution as a workaround for the vulnerability at the following link: KB2639658
This vulnerability does not affect Windows Server 2008 or Windows Server 2008 R2 operating system when they are installed using the Server Core installation option.
Reports suggest that this vulnerability is being exploited by W32.Duqu to install itself on a targeted system. This trojan has been documented in IntelliShield Alert 24425. Microsoft has announced it is investigating this vulnerability. However, no official confirmation is available.
Attackers could leverage the improper processing of a malicious a .doc file as a means to install malicious software. The vulnerability may not exist in the Microsoft Word architecture itself but may be in the font processing capabilities in the Windows kernel.
To exploit the vulnerability, the attacker may provide a file to the user and persuade the user to open or execute the file by using misleading language or instructions. The vulnerability could not be exploited remotely without user interaction.
Vendor Announcements
Microsoft has released a security advisory at the following link: 2639658
Microsoft has released security bulletins at the following links:MS11-087, MS12-034, and MS12-039
US-CERT has released a vulnerability note at the following link: VU#316553
Impact
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code with elevated privileges on a targeted system. If successful, the attacker could completely compromise the system.
Technical Information
The vulnerability is due to improper processing of malformed TrueType fonts by the T2EMBED.DLL library of the Win32k TrueType font parsing engine.
An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious Microsoft Word document (.doc) file embedded with malicious font data. The processing of a malicious file could allow an attacker to execute arbitrary code on the system with the privileges of the user.
Safeguards
Administrators are advised to apply the appropriate updates.
Users are advised not to open e-mail messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in e-mail messages are safe, they are advised not to open them.
Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.
Administrators may consider denying access to the T2EMBED.DLL component.
Administrators may consider using the Microsoft Baseline Security Analyzer (MBSA) scan tool to identify common security misconfigurations and missing security updates on system endpoints.
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 Windows Update website. Microsoft Windows Server Update Services (WSUS), Systems Management Server, and System Center Configuration Manager can assist administrators in deploying software updates.
Alert History
Version 4, May 8, 2012, 5:58 PM: Microsoft has released an additional security advisory and software updates to address the TrueType font parsing remote code execution vulnerability.
Version 3, December 13, 2011, 7:08 PM: Microsoft has released a security advisory to address the TrueType font parsing remote code execution vulnerability.
Version 2, November 4, 2011, 3:30 PM: Microsoft has released a security advisory to address the TrueType font parsing remote code execution vulnerability.
Version 1, November 2, 2011, 9:16 AM: Microsoft Windows contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on a targeted system with elevated privileges. Updates are not available.
Home Edition Base, SP1, SP2, SP3 | Original Release Base, SP1 | Professional Edition Base, SP1, SP2, SP3 | Professional x64 (AMD/EM64T) Base, 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.
