Flash Player Security with Windows 8 and Internet Explorer 10

With the launch of Internet Explorer 10 on Windows 8 last year, customers have experienced improved Flash Player capabilities. Adobe worked closely with Microsoft to integrate Flash Player into Internet Explorer 10 for the Windows 8 platform, but some of our customers are still unaware of the full benefit of the security enhancements. We’d like to take the opportunity to discuss how this integration introduced several new changes that have increased end-user security.

The first significant change is that Flash Player updates for IE 10 on Windows 8 are now distributed through Windows Update. End-users are no longer prompted by the Flash Player auto-updater to update Internet Explorer. This also means that enterprises can now distribute Flash Player updates for Windows 8 through their existing Windows OS patch management workflows. For IE 10 users on Windows 7, you will continue to be updated through Flash Player’s existing update mechanisms.

Windows 8 and IE 10 bring a new level of security known as Enhanced Protected Mode (EPM). In immersive mode, EPM is enabled by default. End users can enable Enhanced Protected Mode on the desktop by selecting Tools > Internet Options > Advanced and checking “Enable Enhanced Protected Mode.”

EPM on IE 10 provides several new protections. One is that all content processes will run as 64-bit processes. This means that Flash Player will also be run as a 64-bit process which will make heap sprays more difficult. The larger address space makes it more difficult to predict the memory location of the spray with a decent statistical likelihood.

The Windows 8 OS security model also utilizes AppContainers for Windows Store. The AppContainer for Internet Explorer 10 is an improvement on the existing idea of Integrity levels. The IE 10 AppContainer brokers both read and write access to most of the operating system. This is an improvement over traditional Protected Mode where only write access was limited. Since Flash Player will be executing as a low privileged process, it will not be able to read user-owned data without user interaction. In addition, the IE 10 AppContainer enforces certain network restrictions which are described here. Since Flash Player is integrated into IE 10, Flash Player is sandboxed by the same AppContainer broker as Internet Explorer.

One aspect of the new AppContainer brokers is that Internet Explorer 10 has an unique cookie store for each mode. Browser cookies for immersive surfing will be placed in the IE 10 AppContainer storage location. Cookies created while surfing Internet-zone content in IE 10 on the desktop will be placed in the Low Integrity Level (LowIL) cookie location. Flash Player acknowledges this paradigm for Local Shared Objects (LSOs), as well. This means that any data stored from your Flash Player gaming in immersive mode will not be available to Flash Player when you are surfing with IE on the desktop. More information on how IE 10 handles cookies on Windows 8 can be found in this blog.

Overall, these new protections serve to further improve security for our Windows 8 customers while also delivering a more streamlined update workflow. Adobe will continue to work with Microsoft to better improve security for our mutual customers going forward.

Peleus Uhley
Platform Security Strategist