Disabling local-with-filesystem access in Flash Player 23

Hey Jeff,

On further review, it looks like we already have a flag for this.

From the System Administrator's Guide (pp26):

http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/flashplayer/pdfs/flash_player_23_0_admin_guide.pdf

AllowUserLocalTrust

This setting lets you prevent users from designating any files on local file systems as trusted (that is, placing them into the local-trusted sandbox). This setting applies to SWF files published for any version of Flash.

AllowUserLocalTrust = [ 0, 1 ] (0=false, 1=true)

If this value is set to 1 (the default), Flash Player allows the user to specify whether local files can be placed into the local-trusted sandbox, through the use of the Settings Manager Global Security Settings panel and user trust files. If this value is set to 0, the user cannot place files into the local-trusted sandbox. That is, the Settings Manager Global Security Settings panel and user trust files are ignored.

If that's not adequate for your needs, please let me know so that we can further consider this.

Thanks!

That's an interesting suggestion.  I'd be happy to nominate it as a feature for a future release.  It does make a lot of sense, and aligns with other administrative capabilities like disabling camera/mic access across an organization.

We know for a fact that there are a lot of educational materials still in the world that rely on local filesytem or CD-ROM playback (I know... educational and industrial training videos are long-lived), and we've heard from a lot of folks this week that have been impacted.  The goal with simply flipping the default, was to significantly reduce the attack surface.  Herd immunity, etc.

For what it's worth, at this point, the user would have to actively download a malicious, crafted SWF, then add it to the local trusted sandbox, and then run it from the local filesystem in order to encounter an attack, at which point, we pop a permission dialog for each request that is made by the SWF to a remote server.  While nonzero, the remaining attack surface is very constrained, and strikes a reasonable balance between functionality and security.

Microsoft Edge has completely done away with loading files from the local filesystem.  If you attempt to do it, they'll just launch IE for compatibility purposes.  I'm curious to see whether that particular feature is a novelty, or if it's ultimately a change that will be mirrored across the modern browser space.