Software Engineering Institute

Adobe Flash Player versions 9.0 through version 18.0.0.204 contain a use-after-free vulnerability in the AS3 opaqueBackground class. This can allow attacker-controlled memory corruption. Exploit code for this vulnerability is publicly available.

Please see Adobe Security Bulletin APSA15-04 for more details about affected Flash versions.

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.

Apply an update

This issue is addressed in Flash Player Desktop 18.0.0.209. See Adobe Security Bulletin APSB15-18 for more details. Please also 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-Play features. 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.