Telnet is really insecure  for remote connection, because passwords are not send proper text format, sending password without encrypted. If you want to access telnet, Use text editor vi, or vim for exit the below files and command that following lines.

# vim /etc/pam.d/login 

# vim /etc/pam.d/remote 
auth       required 

Change to
# auth       required

Now, run the below command, give username is root and root password.
# telnet

Connected to
Escape character is '^]'.
Fedora release 20 (Heisenbug)
Kernel 3.18.7-100.fc20.i686 on an i686 (0)
localhost login: root
Last login: Wed Sep 16 18:04:56 from localhost