Have a look at https://github.com/opinkerfi/adagios/wiki/Users-guide#access-control
on how to enable access-control.
Since there are about 1000 ways to leak sensitive data via configuration, the only secure way we have of restricting access to passwords, is limiting access to configuration stuff only.
If you enable authorization, and then add to administrators group the users who should have full access, other users will no longer see configuration data, and therefore not see the check_command field anymore.
I hope this helps.