Adobe Flash ActionScript 3 opaqueBackground use-after-free vulnerability

Overview

Adobe Flash Player contains a vulnerability in the ActionScript 3 opaqueBackground property, which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.

Description

Adobe Flash Player versions 9.0 through version 18.0.0.203 contain a use-after-free vulnerability in the AS3 opaqueBackground class. This can allow attacker-controlled memory corruption.

Impact

An attacker can execute arbitrary code in the context of the user running Flash Player. Attacks typically involve enticing a user to visit a web site containing specially-crafted Flash content, or to open a specially-crafted Microsoft Office document.

Solution

The CERT/CC is currently unaware of a practical solution to this problem. Please consider the following workarounds:

Do not run untrusted Flash content To defend against this and other, as yet unknown vulnerabilities, disable Flash in your browser or enable Click-to-Playfeatures. Adobe has also provided instructions for how to uninstall Flash on Windows and Mac platforms. Use the Microsoft Enhanced Mitigation Experience Toolkit The Microsoft Enhanced Mitigation Experience Toolkit (EMET) can be used to help prevent exploitation of this vulnerability. In particular, Attack Surface Reduction (ASR) can be configured to help restrict Microsoft Office and Internet Explorer from loading the Flash ActiveX control.

Vendor Information (Learn More)

Vendor	Status	Date Notified	Date Updated
Adobe	Affected	-	11 Jul 2015

If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group	Score	Vector
Base	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P
Temporal	7.5	E:H/RL:U/RC:C
Environmental	7.5	CDP:ND/TD:ND/CR:ND/IR:ND/AR:ND

References

• https://helpx.adobe.com/security/products/flash-player/apsa15-04.html
• https://www.fireeye.com/blog/threat-research/2015/07/cve-2015-5122_-_seco.html
• https://krebsonsecurity.com/2015/07/adobe-to-fix-another-hacking-team-zero-day/
• http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/display/DisplayObject.html#opaqueBackground
• http://www.microsoft.com/emet
• http://www.howtogeek.com/188059/how-to-enable-click-to-play-plugins-in-every-web-browser
• https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html
• https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html

Credit

This document was written by Will Dormann.

Other Information

• CVE IDs: CVE-2015-5122
• Date Public: 05 7월 2015
• Date First Published: 11 7월 2015
• Date Last Updated: 11 7월 2015
• Document Revision: 15