Vulnerability Note VU#230057

Adobe Flash Player contains unspecified code execution vulnerability

Original Release date: 12 Apr 2011 | Last revised: 21 Apr 2011

Overview

Adobe Flash contains a vulnerability that can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.

Description

The following versions of Adobe Flash versions contain an unspecified vulnerability that can result in memory corruption:

  • Adobe Flash Player 10.2.153.1 and earlier versions for Windows, Macintosh, Linux and Solaris operating systems
  • Adobe Flash Player 10.2.154.25 and earlier for Google Chrome users
  • Adobe Flash Player 10.2.156.11 and earlier for Android
  • The Authplay.dll component that ships with Adobe Reader and Acrobat X (10.0.2) and earlier 10.x and 9.x versions for Windows and Macintosh operating systems.
This vulnerability is being actively exploited in the wild. Exploit code for this vulnerability is publicly available as well.

Any application that supports Flash or provides its own runtime may be vulnerable. Updating Flash Player does not update the Flash runtime included in those products. Note that separate instances of Flash are provided in a variety of Adobe products, including Adobe Reader and Acrobat. Adobe states that Adobe Reader 9.x for UNIX, Adobe Reader for Android, and Adobe Reader and Acrobat 8.x are not affected by this issue.

Impact

By convincing a user to view a specially crafted HTML document (e.g., a web page or an HTML email message or attachment), PDF file, Microsoft Office document, or any other document that supports embedded SWF content, an attacker may be able to execute arbitrary code.

Solution

Apply an update
This issue is addressed in Adobe Flash Player 10.2.159.1. Please see Adobe Security bulletin APSB11-07 for more details. Adobe Reader 9.4.4 and Reader X 10.0.3 provide an updated Flash runtime to address this issue. Please see Adobe Security Bulletin APSB11-08 for more details. Please also consider the following workarounds to mitigate this and other Flash vulnerabilities:

Use the Microsoft Enhanced Mitigation Experience Toolkit


The Microsoft Enhanced Mitigation Experience Toolkit (EMET) can be used to help prevent exploitation of this and other vulnerabilities. Additional information can be found in the Microsoft Security Research & Defense blog. Additional workarounds include:

Disable Flash in your web browser

Disable Flash or selectively enable Flash content as described in Securing Your Web Browser.

Disable Flash and 3D & Multimedia support in Adobe Reader 9 and later

Flash and 3D & Multimedia support are implemented as plug-in libraries in Adobe Reader. Disabling Flash in Adobe Reader will only mitigate attacks that use an SWF embedded in a PDF file. Disabling 3D & Multimedia support does not directly address the vulnerability, but it does provide additional mitigation and results not in a crash but in a more user-friendly error message.

To disable Flash and 3D & Multimedia support in Adobe Reader 9 on Microsoft Windows, delete or rename these files:

    "%ProgramFiles%\Adobe\Reader 9.0\Reader\authplay.dll"
    "%ProgramFiles%\Adobe\Reader 9.0\Reader\rt3d.dll"
For Apple Mac OS X, delete or rename these files:
    "/Applications/Adobe Reader 9/Adobe Reader.app/Contents/Frameworks/AuthPlayLib.bundle"
    "/Applications/Adobe Reader 9/Adobe Reader.app/Contents/Frameworks/Adobe3D.framework"
For GNU/Linux, delete or rename these files (locations may vary among distributions):
    "/opt/Adobe/Reader9/Reader/intellinux/lib/libauthplay.so"
    "/opt/Adobe/Reader9/Reader/intellinux/lib/librt3d.so"
NOTE: Adobe states that this particular vulnerability does not affect the authplay component supplied with Reader for Linux. The steps listed above are being provided for users who wish to proactively disable the 3D and multimedia support in the version of Reader for Linux.
For versions of Adobe Reader newer than 9, please adjust the above file paths accordingly. File locations may be different for Adobe Acrobat or other Adobe products that include Flash and 3D & Multimedia support. Disabling these plug-ins will reduce functionality and will not protect against SWF files 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.

Remove Flash

Adobe has provided a TechNote with utilities for uninstalling the Flash Player plug-in and ActiveX control on Windows and Mac OS X systems. Removing these components can mitigate the web browser attack vector for this vulnerability. Note that this will not remove the instances of Flash Player that are installed with Adobe Reader or other Adobe products.

Disable JavaScript in Adobe Reader and Acrobat

Disabling JavaScript can help mitigate some techniques that use Adobe Reader as an attack vector.

To disable JavaScript in Adobe Reader:
  1. Open Adobe Acrobat Reader.
  2. Open the Edit menu.
  3. Choose the Preferences... option.
  4. Choose the JavaScript section.
  5. Uncheck the Enable Acrobat JavaScript checkbox.
Disabling JavaScript will not resolve the vulnerabilities, it will only disable the vulnerable JavaScript component. When JavaScript is disabled, Adobe Reader and Acrobat prompt to re-enable JavaScript when opening a PDF that contains JavaScript.

Prevent Internet Explorer from automatically opening PDF documents

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 the safer option of prompting the user by importing the following as a .REG file:
    Windows Registry Editor Version 5.00

    [HKEY_CLASSES_ROOT\AcroExch.Document.7]
    "EditFlags"=hex:00,00,00,00
Disable the displaying of PDF documents in the web browser

Preventing PDF documents from opening inside a web browser reduces the attack surface. If this workaround is applied to updated versions of Adobe Reader and Acrobat, it may protect against future vulnerabilities.

To prevent PDF documents from automatically opening in a web browser with Adobe Reader:
  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.
Enable DEP in Microsoft Windows

Consider enabling Data Execution Prevention (DEP) in supported versions of Windows. DEP should not be treated as a complete workaround, but it can mitigate the execution of attacker-supplied code in some cases. Microsoft has published detailed technical information about DEP in Security Research & Defense blog posts "Understanding DEP as a mitigation technology" part 1 and part 2. DEP should be used in conjunction with the application of patches or other mitigations described in this document.

Vendor Information (Learn More)

VendorStatusDate NotifiedDate Updated
AdobeAffected-21 Apr 2011
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A

References

Credit

Thanks to Adobe for reporting this vulnerability.

This document was written by Will Dormann.

Other Information

  • CVE IDs: CVE-2011-0611
  • Date Public: 11 Apr 2011
  • Date First Published: 12 Apr 2011
  • Date Last Updated: 21 Apr 2011
  • Severity Metric: 46.47
  • Document Revision: 15

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