No access to CIFS share with multiple windows sessions

[JDEN]

Dear all,

We have noticed a strange behaviour when connecting a Legacy NetApp filer (7-mode 8.2) from Windows 10 systems. This behaviour is noticed as of half way Januari 2022. 
We are known with the fact that when you use multiple user credentials to connect to a single NetApp this waill fail unless you would use a different name (alias or IP)  for that same target.  It's by design that Windows can use only one credetialset to target a certain server.
As of early this year 2022, the behaviour changed and now even if the connection are done within diffrent logon sessions on the same source client system, we also get the access denied problem?

So we have:

old situation 01:

1-Windows10-system_A: User_A has a logon session_A and connects as user_A share A on NetApp_01 => works
2-Windows10-system_A: User_A has a logon session_A and connects as user_B  share B on NetApp_01 => access denied (Windows tries to use the first credential-set of user_A to connect to share_B... this results in access denied)

new situation 02: (also the  situation 01 is still valid)
1-Windows10-system_A: User_A has a logon session_A and connects as user_A share A on NetApp_01 => works
2-Windows10-system_A: User_B has a logon session_B and connects as user_B  share B on NetApp_01 => access denied ??

3-Windows10-system_A: User_A signs-out of Windows10-system_A...

4-Windows10-system_A: User_B now HAS access to the share_B ??

It now seems like ther can only be 1 credential set for the all Windows logon sessions together??

Is this a BUG??? 
Are there new Windows security patches that result in this situation?

Any idea's?

regards,

JDEN

[NetApp_SR · Accepted solution]

The security update for Windows 10 on January 11, 2022 lists "miscellaneous security improvements" as the change. To test if this is the issue you can temporarily uninstall the update to see if the behavior changes.  I suggest this only to confirm an update is the cause of the issue. Security updates are important protection for your system. If this does resolve the issue look for the specific changes and make only the necessary exceptions to the security settings with the current updates installed.

January 11, 2022—KB5009585
https://support.microsoft.com/en-us/topic/january-11-2022-kb5009585-os-build-10240-19177-c56dd31a-42be-4214-b661-10faaa3f24a8

Uninstall security update KB5009543 in Windows 10
https://docs.microsoft.com/en-us/answers/questions/693694/unistaill-security-update-kb5009543-in-windows-10.html

[DarrenJ]

@JDENWhere you ever able to test the security update as suggested previously?