Help: locked out from SSH access as root while trying to disable root access as SSH

Hi,

I wanted to disable SSH root login and only enable it for the admin user

I had admin user properly setup and with SSH shell enabled. I tested and admin user was able to escalate to root by su

I tried to edit the /etc/ssh/sshd_config file, but the changes were reverted each time the SSH service was toggled on/off

I tried to modify the /etc/default/config/etc/ssh/sshd_config but the changes do not apply to the /etc/sshd_config

So it seems the config is regenerated from elesewhere when the SSH service is toggled on/off in GUI

I sadly followed an old guide here and edited the /etc/passwd file

https://community.netgear.com/t5/Using-your-ReadyNAS-in-Business/SSH-Deactivate-root-account-and-use-a-quot-non-root-quot-one/m-p/786272#M5902

I changed the :/bin/bash for root user to :/bin/false

As expected, root can no longer access the shell through SSH. However, admin account cannot escalate to root using su now. The password is accepted, but it doesn't escalate to root. Well, that was expected, but I thought it was a Netgear custom thing. I guess it was fixed in later OS as the guide is dated 2011

Please any one help me reset the access as it is now lost. I will try OS reinstall, but I really want to avoid a hard reset :-(

Also, is this guide uptodate for fixing my issue? (last post of this thread)

https://community.netgear.com/t5/Using-your-ReadyNAS-in-Business/SSH-Configuration-reset-on-reboot/m-p/1181843/highlight/true

Thank you