Public Vulnerability Reports

Adobe Acrobat Professional And Reader AcroJS Heap Corruption Vulnerability

04.11.08

BACKGROUND

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

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

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

DESCRIPTION

Remote exploitation of a heap corruption vulnerability in Adobe Systems Inc.'s Acrobat Professional and Reader could allow an attacker to execute arbitrary code with the privileges of the current user.

The vulnerable code is an AcroJS function available to scripting code inside of a PDF document. This function is used for HTTP authentication. By passing a long string to this function, it is possible to corrupt heap memory in such a way that may lead to the execution of arbitrary code.

ANALYSIS

Exploitation of this vulnerability would allow an attacker to execute arbitrary code with the privileges of the current user. In order to exploit this vulnerability, an attacker would have to convince the target to open a maliciously constructed file, or to visit a website with an embedded PDF. If the user has the Adobe Reader Browser plugin enabled, the PDF file will render inside of the browser.

DETECTION

iDefense has confirmed the existence of this vulnerability in Acrobat Professional and Adobe Reader version 8.1.2. Previous versions may also be affected.

WORKAROUND

Disabling JavaScript in Adobe Reader or Acrobat will limit exposure to this vulnerability. When JavaScript is disabled, Adobe Reader will prompt the user that some components of the document may not function, and provide an opportunity to enable it.

VENDOR RESPONSE

Adobe reports that the input validation issue in the Download Manager used by Adobe Reader has been resolved and has released a patch which addresses this issue. A patch is available from the vendor at:

http://www.adobe.com/support/security/bulletins/apsb08-19.html

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2008-4817 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

03/21/2008 Initial Vendor Notification
04/28/2008 Additional iDefense Data Provided to Vendor
06/26/2008 Additional Vendor Follow-up
11/04/2008 Coordinated Public Disclosure

CREDIT

This vulnerability was reported to iDefense by an anonymous contributor.

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LEGAL NOTICES

Copyright © 2008 Verisign, Inc.

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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.