Adobe Flash contains a vulnerability in the handling of the ActionScript, AVM1 ActionPush command, which can allow a remote, unauthenticated attacker to execute arbitrary code.
Adobe Flash supports two main types of ActionScript, which is the scripting language for Flash. ActionScript 3.0 is supported by the ActionScript Virtual Machine 2 (AVM2), while previous versions are supported by the ActionScript Virtual Machine 1 (AVM1). Flash 9 and later provide both AVM versions for compatibility with both ActionScript varieties. The AVM1 implementation provided with Flash 10.1 contains a vulnerability in the handling of the ActionPush command, which can result in stack corruption. Previous versions of Flash do not appear to be affected.
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.
Apply an update
This issue is addressed in Adobe Flash Player 10.1.82.76, AIR 2.0.3, and Flash CS3 9.0.280. Please see Adobe Security Bulletin APSB10-16 for more details.
Disable Flash in your web browser
Disable Flash or selectively enable Flash content as described in Securing Your Web Browser.
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
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:
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.
This vulnerability was reported by Will Dormann of the CERT/CC.
This document was written by Will Dormann.
|Date First Published:||2010-08-10|
|Date Last Updated:||2012-03-28 14:44 UTC|