-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 iDefense Security Advisory 07.28.09 http://labs.idefense.com/intelligence/vulnerabilities/ Jul 28, 2009 I. BACKGROUND HTML+TIME (HTML Timed Interactive Multimedia Extensions)is a web standard that was created for Microsoft Corp.'s Internet Explorer (IE) to allow web page authors to create timed animation content on a web page. This is accomplished using an XML like markup that makes use of HTML+TIME properties and elements. Internet Explorer supports this markup standard, and also exposes a scripting interface for interacting with the HTML+TIME elements on the page. For more information, please see the vendor's web page at the following link: http://technet.microsoft.com/en-us/library/ms533099(VS.85).aspx II. DESCRIPTION Remote exploitation of a use after free vulnerability in Microsoft Corp.'s Internet Explorer could allow an attacker to execute arbitrary code with the privileges of the current user. The vulnerability occurs when the 'ondatasetcomplete' event method of a timeChildren object is referenced. If this occurs when the object is in an inconsistent state, a heap chunk will be freed, and then reused after being freed. This results in an uninitialized VTABLE being used, which can result in the execution of arbitrary code when the pointer is dereferenced. III. ANALYSIS Exploitation of this vulnerability results in the execution of arbitrary code with the privileges of the user viewing the web page. To exploit this vulnerability, a targeted user must load a malicious web page created by an attacker. An attacker typically accomplishes this via social engineering or injecting content into compromised, trusted sites. After the user visits the malicious web page, no further user interaction is needed. IV. DETECTION iDefense has confirmed the existence of this vulnerability in Internet Explorer versions 6, 7, and 8. Internet Explorer 5 does not appear to be vulnerable. V. WORKAROUND Since this vulnerability is triggered through script code, disabling Active Scripting will prevent the exploitation of this vulnerability. VI. VENDOR RESPONSE Microsoft Corp. has released an Out-Of-Band patch which addresses this issue. Information about downloadable vendor updates can be found by clicking on the URLs shown. http://www.microsoft.com/technet/security/Bulletin/MS09-034.mspx VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2009-1917 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 05/06/2009 - PoC Requested 06/06/2009 - PoC Sent 06/24/2009 - Tentative disclosure set to August 06/25/2009 - Requested CVE from vendor 06/25/2009 - Received CVE from vendor 07/23/2009 - Received updated disclosure notice for OOB in July 07/28/2009 - Coordinated public disclosure IX. CREDIT This vulnerability was reported to iDefense by Peter Vreugdenhil. Get paid for vulnerability research http://labs.idefense.com/methodology/vulnerability/vcp.php Free tools, research and upcoming events http://labs.idefense.com/ X. LEGAL NOTICES Copyright © 2009 iDefense, Inc. Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDefense. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please e-mail customerservice@xxxxxxxxxxxx for permission. Disclaimer: The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iD8DBQFKe0W1bjs6HoxIfBkRAlQLAKCJHohcKfI8Emv5OfSk7LMotPL/7ACfb4Wa JyhMGxPvQ4AfdaK6dfmcIlg= =OPoC -----END PGP SIGNATURE-----
