iDefense Security Advisory 02.24.09: Adobe Flash Player Invalid Object Reference Vulnerability


-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 iDefense Security Advisory 02.24.09 http://labs.idefense.com/intelligence/vulnerabilities/ Feb 24, 2009 I. BACKGROUND Adobe Flash Player is a very popular web browser plugin. It is available for multiple web browsers and platforms, including Windows, Linux and MacOS. Flash Player enables web browsers to display rich multimedia content, such as online videos, and is often a requirement for popular websites. For more information, see the vendor's site found at the following link. http://www.adobe.com/products/flashplayer II. DESCRIPTION Remote exploitation of a invalid object reference vulnerability in Adobe Systems Inc.'s Flash Player could allow an attacker to execute arbitrary code with the privileges of the current user. During the processing of a Shockwave Flash file, a particular object can be created, along with multiple references that point to the object. The object can be destroyed and its associated references removed. However a reference can incorrectly remain pointing to the object. The invalid object resides in uninitialized memory, which the attacker may control to gain arbitrary execution control. 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 Shockwave Flash file created by an attacker. An attacker typically accomplishes this via social engineering or injecting content into a compromised, trusted site. Utilizing various techniques, an attacker is able to re-allocate and control the memory used by the destroyed object. This allows the attacker to subvert execution when a virtual function is called via the invalid reference. IV. DETECTION iDefense has confirmed the existence of this vulnerability in latest version of Flash Player, version Previous versions may also be affected. Exploitation of this vulnerability was tested on Windows XP SP3 and Windows Vista SP1. iDefense believe that all platforms supported by Flash Player are affected by this vulnerability, including Linux and MacOS. V. WORKAROUND A Internet Explorer plugin is available to temporarily block and unblock Flash content using a single click. Only trusted sites should be unblocked when using this plugin. More information is available at http://flash.melameth.com. A Firefox plugin is available to temporarily block and unblock Flash content using a single click. Only trusted sites should be unblocked when using this plugin. More information is available at: http://flashblock.mozdev.org. VI. VENDOR RESPONSE Adobe has released a patch which addresses this issue. For more information, consult their advisory (APSB09-01) at the following URL: http://www.adobe.com/support/flashplayer/ VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2009-0520 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 08/25/2008 - Initial Contact 09/22/2008 - PoC Requested 11/05/2008 - PoC Sent 11/06/2008 - Clarification requested 12/05/2008 - Clarification Sent 12/07/2008 - Additional Clarification Sent 02/19/2009 - Draft bulletin received 02/24/2009 - Coordinated Public Disclosure IX. CREDIT This vulnerability was reported to iDefense by Javier Vicente Vallejo, http://www.vallejo.cc. 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@idefense.com 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 iD8DBQFJpD1jbjs6HoxIfBkRApISAJwPJQ+NVFVuunwT3xQ8oBwPOBIgKACfR6FI CDuo0gjNPYmFcp/qNk0zL/g= =3Cf1 -----END PGP SIGNATURE-----