Microsoft Internet Explorer contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on a targeted system. Updates are available.
Microsoft Internet Explorer 10 contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on a targeted system.
The vulnerability is due to errors in handling memory resources when processing HTML content. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious website. If successful, the attacker could execute arbitrary code on the system with the privileges of the user.
Microsoft confirmed the vulnerability and released software updates.
Microsoft Internet Explorer version 10 is vulnerable when running Windows 8, Windows RT, or Windows Server 2012.
To exploit the vulnerability, the attacker may provide a link that directs a user to a malicious site and use misleading language or instructions to persuade the user to follow the provided link.
Microsoft has released a security bulletin at the following link: MS12-077
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code on the targeted system with the privileges of the user. If the user holds elevated privileges, the attacker could completely compromise the system.
The vulnerability is due to failure to properly maintain reference counts for objects in memory used by Internet Explorer.
An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious website. The processing of the malicious website could cause a reference count error, possibly causing Internet Explorer to access a previously removed or uninitialized memory object. The attacker could use memory corruption resulting from the use-after-free error to execute arbitrary code on the system with the privileges of the user.
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. Alternately, administrators could disable Active Scripting and ActiveX controls in these security zones.
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 monitor affected systems.
Administrators may consider using the Microsoft Baseline Security Analyzer (MBSA) scan tool to identify common security misconfigurations and missing security updates on system endpoints.
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.
Original Release Base
Windows Server 2012
Original Release Base
for 32-bit systems Base | for x64-based systems Base
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.