#StackBounty: #windows #internet-explorer #flash #windows-10 #internet-explorer-11 Internet explorer ignores flash mms.cfg settings

Bounty: 50

I have the following mms.cfg in

  • %localappdata%GoogleChromeUser DataDefaultPepper DataShockwave FlashSystemmms.cfg
  • %localappdata%MicrosoftEdgeUser DataDefaultPepper DataShockwave FlashSystemmms.cfg
  • %windir%System32MacromedFlashmms.cfg
  • %windir%SysWOW64MacromedFlashmms.cfg
EOLUninstallDisable=1
SilentAutoUpdateEnable=0
EnableAllowList=1
AutoUpdateDisable=0
AllowListUrlPattern=http://localhost/flash/
ErrorReportingEnable=1
EnableInsecureLocalWithFileSystem=1

With this after I set my PC date to something in 2021. I’m able to run Flash in

  • Chrome – Which uses the config in %localappdata%GoogleChromeUser DataDefaultPepper DataShockwave FlashSystemmms.cfg
  • Edge Chromium – Which uses the config in %localappdata%MicrosoftEdgeUser DataDefaultPepper DataShockwave FlashSystemmms.cfg
  • Firefox – %windir%System32MacromedFlashmms.cfg

Based on my understanding IE11 should be using the one from %windir%System32MacromedFlashmms.cfg but for whatever reason it seems like it’s ignoring it and the settings in this file have no effect and flash is still disabled.
enter image description here

Just to be on the 100% sure that IE uses that config file I’ve ran ProcMon and it seems like IE is actually opening the file as you can see in the picture.
enter image description here

My question is why is internet explorer ignoring this? And what can I do about it?
Other useful info:

  • Firefox and Chromium browsers use 32.0.0.433
  • IE11 uses 32.0.0.387 which is the windows embedded version of flash.
  • Running windows 10 Pro Version 10.0.18362 N/A Build 18362, experiencing the same behavior on Windows 10 Pro 10.0.19041 N/A Build 19041

Things I’ve tried and didn’t work include:

  • Restarting the machine
  • Setting the encoding of the .cfg to UTF-8.


Get this bounty!!!

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