Microsoft Internet Explorer Vector Markup Language Buffer Overflow Vulnerability

Description

Microsoft Internet Explorer is prone to a buffer-overflow vulnerability that arises because of an error in the processing of Vector Markup Language documents. An attacker can exploit this issue to execute arbitrary code within the context of the affected application. The method currently used to exploit this issue will typically terminate Internet Explorer. This vulnerability is currently being exploited in the wild as ‘Trojan.Vimalov’. This vulnerability affects Internet Explorer version 6.0 on a fully patched system. Previous versions may also be affected. Update: Microsoft Outlook 2003 is also an attack vector for this issue, since it uses Internet Explorer to render HTML email. Reportedly, attacks are possible even when active scripting has been disabled for email viewing.

Technologies Affected

• Avaya Modular Messaging (MAS) 3.0.0
• Avaya Modular Messaging (MAS)
• Avaya S8100 Media Servers
• Avaya S8100 Media Servers R10
• Avaya S8100 Media Servers R11
• Avaya S8100 Media Servers R12
• Avaya S8100 Media Servers R6
• Avaya S8100 Media Servers R7
• Avaya S8100 Media Servers R8
• Avaya S8100 Media Servers R9
• HP Storage Management Appliance 2.1
• Microsoft Internet Explorer 5.0.1 SP4
• Microsoft Internet Explorer 6.0
• Microsoft Internet Explorer 6.0 SP1
• Microsoft Outlook 2003
• Microsoft Windows 2000 Advanced Server
• Microsoft Windows 2000 Advanced Server SP1
• Microsoft Windows 2000 Advanced Server SP2
• Microsoft Windows 2000 Advanced Server SP3
• Microsoft Windows 2000 Advanced Server SP4
• Microsoft Windows 2000 Datacenter Server
• Microsoft Windows 2000 Datacenter Server SP1
• Microsoft Windows 2000 Datacenter Server SP2
• Microsoft Windows 2000 Datacenter Server SP3
• Microsoft Windows 2000 Datacenter Server SP4
• Microsoft Windows 2000 Professional
• Microsoft Windows 2000 Professional SP1
• Microsoft Windows 2000 Professional SP2
• Microsoft Windows 2000 Professional SP3
• Microsoft Windows 2000 Professional SP4
• Microsoft Windows 2000 Server
• Microsoft Windows 2000 Server SP1
• Microsoft Windows 2000 Server SP2
• Microsoft Windows 2000 Server SP3
• Microsoft Windows 2000 Server SP4
• Microsoft Windows Server 2003 Datacenter Edition
• Microsoft Windows Server 2003 Datacenter Edition Itanium
• Microsoft Windows Server 2003 Datacenter Edition Itanium SP1
• Microsoft Windows Server 2003 Datacenter Edition Itanium SP1 Beta 1
• Microsoft Windows Server 2003 Datacenter Edition SP1
• Microsoft Windows Server 2003 Datacenter x64 Edition
• Microsoft Windows Server 2003 Enterprise Edition
• Microsoft Windows Server 2003 Enterprise Edition Itanium
• Microsoft Windows Server 2003 Enterprise Edition Itanium SP1
• Microsoft Windows Server 2003 Enterprise Edition Itanium SP1 Beta 1
• Microsoft Windows Server 2003 Enterprise Edition SP1
• Microsoft Windows Server 2003 Enterprise x64 Edition
• Microsoft Windows Server 2003 Standard Edition
• Microsoft Windows Server 2003 Standard Edition SP1
• Microsoft Windows Server 2003 Standard x64 Edition
• Microsoft Windows Server 2003 Web Edition
• Microsoft Windows Server 2003 Web Edition SP1
• Microsoft Windows XP 64-bit Edition
• Microsoft Windows XP 64-bit Edition SP1
• Microsoft Windows XP 64-bit Edition Version 2003
• Microsoft Windows XP 64-bit Edition Version 2003 SP1
• Microsoft Windows XP
• Microsoft Windows XP Home
• Microsoft Windows XP Home SP1
• Microsoft Windows XP Home SP2
• Microsoft Windows XP Media Center Edition
• Microsoft Windows XP Media Center Edition SP1
• Microsoft Windows XP Media Center Edition SP2
• Microsoft Windows XP Professional
• Microsoft Windows XP Professional SP1
• Microsoft Windows XP Professional SP2
• Microsoft Windows XP Professional x64 Edition
• Microsoft Windows XP Tablet PC Edition
• Microsoft Windows XP Tablet PC Edition SP1
• Microsoft Windows XP Tablet PC Edition SP2

Recommendations

Run all software as a nonprivileged user with minimal access rights.
Ensure that all non-administrative tasks, such as browsing the web and reading email, are performed as an unprivileged user with minimal access rights.

Do not follow links provided by unknown or untrusted sources.
Users should never visit sites of questionable integrity or follow links provided by unfamiliar or untrusted sources.

Set web browser security to disable the execution of script code or active content.
Disabling scripting and active content in the Internet Zone may limit exposure to this and other vulnerabilities.

Modify default configuration files to disable any unwanted behavior.
Configure email client applications to display email as plaintext only. This will limit the possibility of email-based attacks.

Microsoft has released advisory MS06-055 to address this issue. Please see the referenced advisory for details on obtaining and applying the appropriate updates. Note: A third-party, temporary fix is available from the Zeroday Emergency Response Team (ZERT). Symantec has not verified this fix; Microsoft does not support it. Please see the references for more information.