Additional technical information to describe the Microsoft Internet Explorer CBlockElement objects memory corruption vulnerability is available.
A vulnerability in Microsoft Internet Explorer could allow an unauthenticated, remote attacker to execute arbitrary code.
The vulnerability is due to improper memory operations performed by the affected software when handling CBlockElement objects. An unauthenticated, remote attacker could exploit this vulnerability by persuading a user to view a malicious website. A successful exploit could allow the attacker to execute arbitrary code with the privileges of the user. If the user holds elevated privileges, the attacker could completely compromise the targeted system.
Microsoft has confirmed the vulnerability in a security bulletin and released software updates.
Microsoft Internet Explorer versions 9 and 10 are vulnerable when running on the following Microsoft products:
Windows Vista and x64 Edition SP2
Windows Server 2008 for 32-bit and x64-based Systems SP2
Windows 7 for 32-bit and x64-based Systems SP1
Windows Server 2008 R2 for x64-based Systems SP1
Windows 8 for 32-bit and x64-based Systems
Windows Server 2012
To exploit the vulnerability, the attacker may provide a link that directs a user to a malicious site and may use misleading language or instructions to convince the user to follow the link.
Microsoft has corrected the vulnerability by modifying how the affected software performs memory operations when handling crafted content.
Microsoft has released a security bulletin at the following link: MS13-069
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code with the privileges of the user. If the user holds elevated privileges, the attacker could completely compromise the targeted system.
The vulnerability is due to a memory corruption error that may occur when the affected software is handling CBlockElement objects and using MutationEvents on pop-up windows.
An unauthenticated, remote attacker could exploit this vulnerability by providing a document with crafted elements to a user and persuading the user to open the document or follow a crafted link. When the affected software processes the malicious document elements, the software may attempt to reuse a dangling pointer that was previously freed in memory, leading to a memory corruption error that could allow the attacker to execute arbitrary code with the privileges of the user. If the user holds elevated privileges, the attacker could completely compromise the targeted system.
Administrators are advised to apply the appropriate updates.
Administrators may consider configuring Internet Explorer to prompt users before running Active Scripting or ActiveX controls by setting the Internet and Local Intranet security zone settings to High. Alternatively, administrators could disable Active Scripting and ActiveX controls in these security zones.
Users are advised not to open email messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in email messages are safe, they are advised not to open them.
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.
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.
9.0 Base | 10.0 Base
for 32-bit systems SP1 | for x64-based systems SP1
Original Release Base
Windows Server 2008
Datacenter Edition SP2 | Datacenter Edition, 64-bit SP2 | Enterprise Edition SP2 | Enterprise Edition, 64-bit SP2 | Essential Business Server Standard SP2 | Essential Business Server Premium SP2 | Essential Business Server Premium, 64-bit SP2 | Standard Edition SP2 | Standard Edition, 64-bit SP2 | Web Server SP2 | Web Server, 64-bit SP2
Windows Server 2008 R2
x64-Based Systems Edition SP1
Windows Server 2012
Original Release Base
Home Basic SP2 | Home Premium SP2 | Business SP2 | Enterprise SP2 | Ultimate SP2 | Home Basic x64 Edition SP2 | Home Premium x64 Edition SP2 | Business x64 Edition SP2 | Enterprise x64 Edition SP2 | Ultimate x64 Edition SP2
for 32-bit systems Base | for x64-based systems Base
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