iDefense Security Advisory 09.13.11
http://labs.idefense.com/intelligence/vulnerabilities/
Sep 13, 2011

I. BACKGROUND

Adobe Reader and Acrobat are portable document format (PDF) readers and
processors. For more information, please visit the following pages:
http://www.adobe.com/products/reader/
http://www.adobe.com/products/acrobat/

II. DESCRIPTION

Remote exploitation of a use after free vulnerability in Adobe Systems
Inc.'s Reader could allow an attacker to execute arbitrary code with the
privileges of the current user.

The vulnerability occurs when parsing a JPEG file embedded inside a PDF
file. When processing specific JPEG markers, Adobe Reader creates an
object on the stack and keeps a pointer to that object in another place.
The pointer is later dereferenced after the object on the stack becomes
invalid. This can lead to the execution of arbitrary code.

III. ANALYSIS

Exploitation of this vulnerability results in the execution of arbitrary
code with the privileges of the user opening the file. To exploit this
vulnerability, an attacker needs to use social engineering techniques to
trick a user into opening a malicious PDF file. Since PDF files can be
embedded into Web pages and parsed without interaction by default, an
attacker can exploit this vulnerability as a typical browser
vulnerability.

IV. DETECTION

Adobe has reported the following products vulnerable:

* Adobe Reader X (10.1) and earlier 10.x versions for Windows and Macintosh
* Adobe Reader 9.4.5 and earlier 9.x versions for Windows, Macintosh and
UNIX
* Adobe Reader 8.3 and earlier 8.x versions for Windows and Macintosh
* Adobe Acrobat X (10.1) and earlier 10.x versions for Windows and
Macintosh
* Adobe Acrobat 9.4.5 and earlier 9.x versions for Windows and Macintosh
* Adobe Acrobat 8.3 and earlier 8.x versions for Windows and Macintosh

V. WORKAROUND

iDefense is currently unaware of any workarounds for this issue.

VI. VENDOR RESPONSE

Adobe has released fixes which addresses this issue. Information about
downloadable vendor updates can be found by clicking on the URLs shown.

http://www.adobe.com/support/security/bulletins/apsb11-24.html

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2011-2440 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

06/08/2011  Initial Vendor Notification
06/08/2011  Vendor Reply
09/13/2011  Coordinated Public Disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 2011 Verisign

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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.