9.3 - TA08-043A

Adobe has released Security advisory APSA08-01 to address multiple vulnerabilities affecting Adobe Reader and Acrobat. The most severe of these vulnerabilities could allow a remote attacker to execute arbitrary code.

I. Description

Adobe Security advisory APSA08-01 addresses a number of vulnerabilities affecting the Adobe Acrobat family of products, including Adobe Reader. Acrobat versions 8.1.1 and earlier are affected. Further details are available in the US-CERT Vulnerability Notes Database.

An attacker could exploit these vulnerabilities by convincing a user to load a specially crafted Adobe Portable Document Format (PDF) file.
Acrobat integrates with popular web browsers, and visiting a web site is usually sufficient to cause Acrobat to load PDF content.

At least one of these vulnerabilities is being actively exploited. The SANS Internet Storm Center Handler's Diary contains more information.

II. Impact

The impacts of these vulnerabilities vary. The most severe of these vulnerabilities allows a remote attacker to execute arbitrary code.

III. Solution

Upgrade

Upgrade Adobe Reader or Acrobat to version 8.1.2 according to the information in Adobe Security advisory APSA08-01.

Disable web browser display for PDF documents

Preventing PDF documents from opening inside a web browser may mitigate this vulnerability. Applying the following workaround in conjunction with upgrading may prevent similar vulnerabilities from being automatically exploited.

To prevent PDF documents from automatically being opened in a web browser with Acrobat or Reader:
1. Open Adobe Acrobat or Adobe Reader.
2. Open the Edit menu.
3. Choose the Preferences option.
4. Choose the Internet section.
5. De-select the "Display PDF in browser" check box.

Disable automatic opening of PDF documents in Microsoft Internet Explorer

To disable automatic opening of PDF files in Microsoft Internet Explorer (IE), a second step is required. To configure IE to prompt before opening a PDF file, disable the "Display PDF in browser"
feature (as described above) and then make the following changes to the Windows registry:

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\AcroExch.Document.7]
"EditFlags"=hex:00,00,00,00

Disable JavaScript in Adobe Reader and Acrobat

Disabling JavaScript in Adobe Reader and Acrobat may prevent this vulnerability from being exploited. In Acrobat Reader, JavaScript can be disabled in the General preferences dialog (Edit --> Preferences
--> JavaScript, de-select Enable Acrobat JavaScript).