local admin user access privilege set to "1" S4048-ON

I've tried setting a new password for the existing "admin" account on a S4048-ON by logging on to the CLI with the admin account and entering:

console(config)#username admin password newpassword

I've then save the running config to the start up config and rebooted the switch.

After the reboot, I can log on to the CLI using the new password for the admin account, but can't elevate beyond user mode - access level has been set back to "1"

Obviously It's no longer possible to elevate to exec or privileged exec mode with this account, in order to reset the privilege level back to 15. This is also the only user account on the switch, so I can't connect with another account with sufficient privileges to reset it that way either.

Is the only solution to physically connect using a console cable and reset the switch? I don't want to lose the running config on the switch though, so is there any way to back up the running config without the admin account having the correct privilege level to run the "copy" command?