‘Adobe Reader Security Provider Unsafe Libary Path Vulnerability’

Summary

Adobe Reader is ‘a program for viewing Portable Document Format (PDF) documents’. 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.’

Credit:

‘The information has been provided by iDefense Labs.
The original article can be found at: http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=655


Details

Vulnerable Systems:
 * Adobe Reader version 8.1 installed on Windows XP and Windows Vista

Immune Systems:
 * Adobe Reader version 8.1.2

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 Provide 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.

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:
CVE-2007-5666

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’

Categories: Windows