1383086 - Firefox don't start after setting "TransparentEnabled"=dword:00000002

Status: RESOLVED WONTFIX

(Core Graveyard :: Plug-ins, defect, P3)

Description

[ruediger]

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:56.0) Gecko/20100101 Firefox/56.0 SeaMonkey/2.53a1
Build ID: 20170618013735

Steps to reproduce:

I set at Windows10pro Registry:  [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\safer\codeidentifiers] "TransparentEnabled"=dword:00000002
to restrict access to the Macromedia Flash folder (%windir%\system32\Macromed\Flash\)

See: https://technet.microsoft.com/de-de/library/security/ms06-020.aspx


Actual results:

Firefox, Thunderbird and SeaMonkey don't start. After doubleclick on firefox.exe the Cursor-cycle rotates some seconds but Firefox don't start. firefox.exe only appears in Taskmanager and must be killed there.

Last good: 20170416030209
First bad:  20170420030346
There were no Nightly-Builds for Windows in between.


Expected results:

Firefox, Thunderbird and Seamonkey should start.
With "TransparentEnabled"=dword:00000001 Firefox starts.

It looks like only Win 10 is affected.

Comment 1

[Jim Mathies [:jimm]]

Interesting, never read about this. Apparently it's been around since 2006. Here's the full registry edit:

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers]
"TransparentEnabled"=dword:00000002

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Safer\CodeIdentifiers\0\Paths\{2742f840-c2d8-4eb3-a486-0a9d0879f29f}]
"LastModified"=hex(b):10,c3,8a,19,c6,e3,c5,01
"Description"="Block Macromedia Flash"
"SaferFlags"=dword:00000000
"ItemData"=hex(2):25,00,77,00,69,00,6e,00,64,00,69,00,72,00,25,00,5c,00,73,00,\
79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,6d,00,61,00,63,00,72,00,6f,\
00,6d,00,65,00,64,00,5c,00,66,00,6c,00,61,00,73,00,68,00,5c,00,2a,00,00,00

I don't think this is something we need to worry about since flash is now sandboxed. It would be interesting to see why it fails to load though when we have some time.

Comment 2

[ruediger]

(In reply to Jim Mathies [:jimm] from comment #1)

> I don't think this is something we need to worry about since flash is now
> sandboxed.

I'm not familiar with this at all, but 'safer' is also known as 'software restriction polices' https://technet.microsoft.com/library/cc786941.aspx and "TransparentEnabled"=dword:00000002 is (if I understood it right)a command to enable this rules for ALL executables and dll. 00000001 only includes the executables. I think, its not limited only on Macromedia Flash.

So this rule could be part of many Company-Rule-Sets for their Windows-Installations. We use the rule-set from Stefan Kanthak on https://skanthak.homepage.t-online.de/SAFER.html Please contact Stefan for detailed information.

Comment 3

[Christoph Schneegans]

(In reply to Jim Mathies [:jimm] from comment #1)

> I don't think this is something we need to worry about since flash is now
> sandboxed.

Jim, this has nothing to do with Flash. Setting the registry value

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\safer\codeidentifiers]
"TransparentEnabled"=dword:2

immediately triggers this problem even when there are no other value or subkeys in the [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\safer] registry key.

However, it seems that not all versions of Windows 10 are affected. I am able to reproduce this problem in Windows 10 1703, but not in Windows 10 1607, even with an identical Firefox Nightly build. (Testing is easy since the registry setting mentioned above takes effect immediately, so no reboot is required.)

It is noteworthy that Microsoft Edge suffers from a quite similar problem, starting with Windows 10 1703. When "TransparentEnabled"=dword:2 is set, Edge does start, but its UI is crippled, and no tabs can be created.

Comment 4

[ruediger]

(In reply to Christoph Schneegans from comment #3)

Christoph, thank you for your better explanation.

> However, it seems that not all versions of Windows 10 are affected. I am
> able to reproduce this problem in Windows 10 1703, but not in Windows 10
> 1607, even with an identical Firefox Nightly build.

I had this Bug also on a win 10 1511

Comment 5

[Christoph Schneegans]

Attachment: debug.log

Please find attached a log file created by Microsoft's ntsd.exe debugger. Note that the stack trace mentions two functions

· ADVAPI32!SaferpIsV2PolicyPresent
· ADVAPI32!SaferiIsDllAllowed

which are most likely related to the [HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\safer\codeidentifiers] registry key.

Comment 6

[Christoph Schneegans]

Attachment: thunderbird-debug.log

Running the current Thunderbird Daily (downloaded from https://archive.mozilla.org/pub/thunderbird/nightly/latest-comm-central/thunderbird-56.0a1.en-US.win32.installer.exe) in the ntsd.exe debugger produces an almost identical log file, again with functions ADVAPI32!SaferpIsV2PolicyPresent and ADVAPI32!SaferiIsDllAllowed mentioned in the stack trace.

Comment 7

[alex_mayorga]

https://www.adobe.com/products/flashplayer/end-of-life.html