CERT Technical Cyber Security Alert TA11-350A – Adobe Vulnerabilities – Windows, Mac, Unix

A little something to keep you busy…   Adobe vulnerabilities that affect Microsoft Windows, Mac and Unix machines.

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National Cyber Alert System

Technical Cyber Security Alert TA11-350A

Adobe Updates for Multiple Vulnerabilities

Original release date: December 16, 2011

Last revised: —

Source: US-CERT

Systems Affected

* Adobe Reader X (10.1.1) and earlier 10.x versions for Windows and Macintosh

* Adobe Reader 9.4.6 and earlier 9.x versions for Windows, Macintosh, and UNIX

* Adobe Acrobat X (10.1.1) and earlier 10.x versions for Windows and Macintosh

* Adobe Acrobat 9.4.6 and earlier 9.x versions for Windows and Macintosh



Adobe has released Security Bulletin APSB11-30, which describes

multiple vulnerabilities affecting Adobe Reader and Acrobat.


I. Description

Adobe Security Bulletin APSB11-30 and Adobe Security Advisory

APSA11-04 describe a number of vulnerabilities affecting Adobe

Reader and Acrobat. These vulnerabilities affect Reader and Acrobat

9.4.6 and earlier 9.x versions. These vulnerabilities also affect

Reader X and Acrobat X 10.1.1 and earlier 10.x versions.


An attacker could exploit these vulnerabilities by convincing a

user to open a specially crafted PDF file. The Adobe Reader browser

plug-in, which can automatically open PDF documents hosted on a

website, is available for multiple web browsers and operating



Adobe Reader X and Adobe Acrobat X will be patched in the next

quarterly update scheduled for January 10, 2012.


Additional details for the U3D memory corruption vulnerability can

be found in US-CERT Vulnerability Note VU#759307.

II. Impact

These vulnerabilities could allow a remote attacker to execute

arbitrary code, write arbitrary files or folders to the file

system, escalate local privileges, or cause a denial of service on

an affected system as the result of a user opening a malicious PDF



III. Solution

Update Reader

Adobe has released updates to address this issue. Users are

encouraged to read Adobe Security Bulletin APSB11-30 and update

vulnerable versions of Adobe Reader and Acrobat.


In addition to updating, please consider the following mitigations.


Disable Flash in Adobe Reader and Acrobat


Disabling Flash in Adobe Reader will mitigate attacks that rely on

Flash content embedded in a PDF file. Disabling 3D & Multimedia

support does not directly address the vulnerability, but it does

provide additional mitigation and results in a more user-friendly

error message instead of a crash. To disable Flash and 3D &

Multimedia support in Adobe Reader 9, delete, rename, or remove

access to these files:


Microsoft Windows

“%ProgramFiles%\Adobe\Reader 9.0\Reader\authplay.dll”

“%ProgramFiles%\Adobe\Reader 9.0\Reader\rt3d.dll”


Apple Mac OS X

“/Applications/Adobe Reader 9/Adobe


“/Applications/Adobe Reader 9/Adobe



GNU/Linux (locations may vary among distributions)




File locations may be different for Adobe Acrobat or other Adobe

products that include Flash and 3D & Multimedia support. Disabling

these plugins will reduce functionality and will not protect

against Flash content that is hosted on websites. Depending on the

update schedule for products other than Flash Player, consider

leaving Flash and 3D & Multimedia support disabled unless they are

absolutely required.


Disable JavaScript in Adobe Reader and Acrobat


Disabling JavaScript may prevent some exploits from resulting in

code execution. Acrobat JavaScript can be disabled using the

Preferences menu (Edit -> Preferences -> JavaScript; uncheck Enable

Acrobat JavaScript).


Adobe provides a framework to blacklist specific JavaScipt APIs. If

JavaScript must be enabled, this framework may be useful when

specific APIs are known to be vulnerable or used in attacks.


Prevent Internet Explorer from automatically opening PDF files


The installer for Adobe Reader and Acrobat configures Internet

Explorer to automatically open PDF files without any user

interaction. This behavior can be reverted to a safer option that

prompts the user by importing the following as a .REG file:


Windows Registry Editor Version 5.00





Disable the display of PDF files in the web browser


Preventing PDF files from opening inside a web browser will

partially mitigate this vulnerability. If this workaround is

applied, it may also mitigate future vulnerabilities.


To prevent PDF files from automatically being opened in a web

browser, do the following:


1. Open Adobe Acrobat Reader.

2. Open the Edit menu.

3. Choose the Preferences option.

4. Choose the Internet section.

5. Uncheck the “Display PDF in browser” checkbox.


Remove or restrict access to 3difr.x3d


By removing or restricting access to the 3difr.x3d file, Adobe

Reader and Acrobat will fail to render U3D content, which helps to

mitigate this vulnerability. PDF documents that use the PRC format

for 3D content will continue to function on Windows and Linux



To disable U3D support in Adobe Reader 9 on Microsoft Windows,

delete or rename this file:


“%ProgramFiles%\Adobe\Reader 9.0\Reader\plug_ins3d\3difr.x3d”


For Apple Mac OS X, delete or rename this directory:


“/Applications/Adobe Reader 9/Adobe



For GNU/Linux, delete or rename this file (locations may vary among





File locations may be different for Adobe Acrobat or other Adobe

products or versions.


Do not access PDF files from untrusted sources


Do not open unfamiliar or unexpected PDF files, particularly those

hosted on websites or delivered as email attachments. Please see

Cyber Security Tip ST04-010.



IV. References


* Security update available for Adobe Reader and Acrobat –



* Adobe Reader and Acrobat JavaScript Blacklist Framework –



* Adobe Acrobat and Reader U3D memory corruption vulnerability –



* Security Advisory for Adobe Reader and Acrobat –





The most recent version of this document can be found at:





Feedback can be directed to US-CERT Technical Staff. Please send

email to <cert@cert.org> with “TA11-350A Feedback VU#759307” in

the subject.



For instructions on subscribing to or unsubscribing from this

mailing list, visit <http://www.us-cert.gov/cas/signup.html>.



Produced 2011 by US-CERT, a government organization.


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Revision History


December 16, 2011: Initial release




Version: GnuPG v1.4.5 (GNU/Linux)










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