[SSH] auto disconnect after login attempt

posted in: computer | 0

OpenSSH 9.0p1

ssh -v <server>

error message:
Authenticated to <server> ([<ip-adress>]:<port>) using "publickey".
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: client_input_channel_req: channel 0 rtype exit-signal reply 0
debug1: client_input_channel_req: channel 0 rtype eow@openssh.com reply 0
debug1: channel 0: free: client-session, nchannels 1
Connection to <server> closed.
Transferred: sent 2724, received 4244 bytes, in 0.1 seconds
Bytes per second: sent 50774.8, received 79107.2
debug1: Exit status -1

the authentication works, but afterwards the login-process is automatically terminated (channel 0 <...> exit-signal reply 0) and the connection is closed.

possible solution:
After the completed authentication the execution of the user shell is not working or the user shell is not defined (the user has no login shell specified).

1.) check /etc/passwd if a default user login-shell is properly set. If not, define a user shell.

2.) check if the user can execute the shell properly (e.g. login as user and execute the shell from commandline). If the output shows an error, fix the error, reinstall the shell or change the user-shell in /etc/passwd to a working one.

3.) if the user shell is working properly, now the login process should procede properly too.