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EDY-innit
EDY-innit
Participant
June 21, 2017
Answered

NPAPI Flash Player no longer saving/caching

  • June 21, 2017
  • 3 replies
  • 985 views

I recently had a critical OS error forcing a reinstall.

Since doing this and recovering what I could from the previous install, I no longer have any functionality in the Flash cache. I am given the Allow/Deny dialog every time for the same flash application served (accept caching, refresh, dialog returns).

Any settings or other saved information (e.g. game saves and tracked achievements) is confirmed not to persist where reliant on my local machine.

I have uninstalled the Flash player (both NPAPI and PPAPI) and cleaned out all traces of Flash Player from my AppData, then reinstalled the player; this did not solve the issue.

Issue only appears to be happening in NPAPI (firefox). Chrome test of identical application persists information where Firefox does not.

Using latest Firefox version (54) and Flash Player plugins (26.0.0.131).

Have cleared Firefox cache, Flash cache, removed and reinstalled Flash as previously mentioned without solving issue.

    This topic has been closed for replies.
    Correct answer EDY-innit

    Cause of fault: Directory Junction of Windows User folder

    Workarounds to issue: Avoid junctioning User folder; use following steps to direct Windows to use another location without Junction:

    • Enter Registry (preferably on alternative account to avoid issues with running context)

    • Navigate to "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\"

    • Find the current user's subfolder (look at the ProfileImagePath key to recognise User folder path)

    • Alter ProfileImagePath key to point to Junctioned user folder location

    • Remove now unneeded Junction link

    • Upon signing back in to affected account, NO Windows errors should be thrown w/r/t User data being missing/corrupt and Flash Cache should work as no junction is present.

    Workaround confirmed on Windows 10 64bit; Firefox 54.0; Flash Player 26.0.0.131

    3 replies

    jeromiec83223024
    jeromiec83223024
    Inspiring
    June 26, 2017

    Yes.  Having a junction in a path to a user folder can lead to arbitrary writes under certain circumstances.  We disabled support a couple years ago, and require that you set a flag to get the legacy behavior.

    You can find details here:

    Adobe Flash Player Administration Guide for Flash Player | Adobe Developer Connection

    EDY-innit
    EDY-innitAuthor
    Participant
    June 27, 2017

    Thank you for the information. It would be nice if there was a visible notification of this protection being triggered to better inform unwitting users. We can't be expected to know all the minutia of security updates from years ago.

    However, setting that flag does not appear to return correct behaviour in Firefox, even if Protected Mode is disabled for the SWF plugin.

    Also you should probably revisit the code:

    • Depending where the junction was along the path had occasional instances of allowing the files to write (I think I tested it with only "%UserProfile%\AppData\Roaming\Macromedia" junctioned at one point, which is where the files are written, and it did still write)
    • It is notable that even without MMS.cfg override in the location Chrome uses, files still saved underneath the "%UserProfile%\AppData\Local\Google\Chrome\User Data\Default\Pepper Data\Shockwave Flash\WritableRoot\" folder despite junction being on %UserProfile% folder itself. Surely this should trigger the "don't write on a junction path" protection.

    I feel like asking a user to change their system (regedit to avoid junction) to suit a program is strictly considerable as a workaround, not a solution, despite being what the Administration Guide recommends.

    jeromiec83223024
    jeromiec83223024
    Inspiring
    June 27, 2017

    Thanks for your feedback.

    EDY-innit
    EDY-innitAuthorCorrect answer
    Participant
    June 25, 2017

    Cause of fault: Directory Junction of Windows User folder

    Workarounds to issue: Avoid junctioning User folder; use following steps to direct Windows to use another location without Junction:

    • Enter Registry (preferably on alternative account to avoid issues with running context)

    • Navigate to "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\"

    • Find the current user's subfolder (look at the ProfileImagePath key to recognise User folder path)

    • Alter ProfileImagePath key to point to Junctioned user folder location

    • Remove now unneeded Junction link

    • Upon signing back in to affected account, NO Windows errors should be thrown w/r/t User data being missing/corrupt and Flash Cache should work as no junction is present.

    Workaround confirmed on Windows 10 64bit; Firefox 54.0; Flash Player 26.0.0.131

    Vivek Negi
    Adobe Employee
    Vivek Negi
    Adobe Employee
    June 21, 2017

    Hi,

    Please log a bug here Tracker  and share your sample app.

    -Vivek

    Adobe Flash Runtime Team

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