Additional technical information is available that describes the Microsoft Internet Explorer CTreePos object handling use-after-free vulnerability.
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 crafted content. 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.
Internet Explorer 10 is affected when running on the following Microsoft products:
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 64-bit Systems
Windows Server 2012
To exploit the vulnerability, the attacker may provide a link that directs a user to a malicious site or persuade a user to open a malicious file intended to submit malicious input to the affected software.
Microsoft has resolved the vulnerability by correcting the way Internet Explorer handles objects in memory.
Microsoft has released a security bulletin at the following link: MS13-047
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 use-after-free memory corruption error that may occur when Internet Explorer attempts to undo Document Object Model (DOM) manipulations using the execCommand when handling CTreePos objects in memory.
An unauthenticated, remote attacker could exploit this vulnerability by persuading a targeted user to follow a link to a document with crafted elements designed to submit malicious input to the affected software. When the affected software handles the malicious document elements, a dangling pointer may be reused after being freed, leading to a memory corruption error 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 are advised to allow only trusted users to have network access.
Administrators may consider using the Microsoft Baseline Security Analyzer (MBSA) scan tool to identify common security misconfigurations and missing security updates on system endpoints.
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.
Users are advised not to visit websites or follow links that have suspicious characteristics or cannot be verified as safe.
Administrators are advised to use an unprivileged account when browsing the Internet.
Administrators are advised to monitor critical 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.
Version 1, June 11, 2013, 5:27 PM: Microsoft Internet Explorer contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code on a targeted system. Updates are available.
The security vulnerability applies to the following combinations of products.
for 32-bit systems SP1 | for x64-based systems SP1
for 32-bit systems Base | for x64-based systems Base
Original Release Base
Windows Server 2008 R2
x64-Based Systems Edition SP1
Windows Server 2012
Original Release 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.