Public Vulnerability Reports

Adobe Reader Security Provider Unsafe Libary Path Vulnerability

02.08.08

BACKGROUND

Adobe Reader is a program for viewing Portable Document Format (PDF) documents. More information is available at the following URLs.

http://www.adobe.com/products/reader/

DESCRIPTION

Remote exploitation of an unsafe library path vulnerability in Adobe Systems Inc.'s Adobe Reader may allow attackers to execute arbitrary code as the current user.

This vulnerability is due to Adobe Reader using a path for "Security Provider" libraries that contains the directory the application was started in. Security Provider libraries provide encryption and signature verification routines to applications. If the current directory contains a file with the same name as a Security Provider library, the file will be loaded into the application, potentially allowing code execution.

ANALYSIS

Exploitation allows an attacker to execute arbitrary code as the user that started the application. To exploit this vulnerability, the attacker must convince the targeted user to open a PDF from a directory under their control. This directory may be local or network based on either an SMB or WebDAV server. If Adobe Reader has already been started, the library will not be loaded.

DETECTION

iDefense has confirmed this vulnerability exists in Adobe Reader 8.1 installed on Windows XP and Windows Vista. Previous versions, as well as those for other platforms, may also be affected.

WORKAROUND

Copying the original library from "%WINDIR%System32" to the same directory as the AcroRd32.exe binary will make the application find the correct library before a malicious one is found.

The actual filenames which can be used to exploit this vulnerability depend on the operating system and version. To determine which filenames affect your system, consult the following registry key.

 HKLMSystemCurrentControlSetControlSecurityProvidersSecurityProviders 

This is only a temporary workaround; future software updates will not update these copies. As such, the copies should be removed once this vulnerability has been patched.

VENDOR RESPONSE

Adobe has released version 8.1.2 of Adobe Reader that addresses this vulnerability. Although there is currently no update for version 7.0.9, Adobe reports it does plan to release one at a later date. For more information, visit the vendor's advisory at the following URL.

http://www.adobe.com/support/security/advisories/apsa08-01.html

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-5666 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems.

DISCLOSURE TIMELINE

09/25/2007 Initial vendor notification
09/25/2007 Initial vendor response
10/26/2007 Request for status
10/26/2007 Status - Est. early January
01/04/2008 Request for status
01/04/2008 Status - Scheduled early February
01/28/2008 Adobe plans patch for 8, but not 7
01/30/2008 Concerns about the plan e-mailed to Adobe
01/31/2008 Telephone call to clarify concerns
02/06/2008 Adobe releases 8.1.2
02/07/2008 Adobe publishes APSA08-01
02/08/2008 Public disclosure

CREDIT

This vulnerability was discovered by Greg MacManus of VeriSign iDefense Labs.

Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com/

LEGAL NOTICES

Copyright © 2008 Verisign, 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 customer service 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.