Only root is able to login

[Thomas Krause]

Hello,
I've a big problem, that only root is able to login to a new FreeBSD 5.2.1
box. Neither login nor su works. I've no local access to the machine.
A ftp-login is possible for normal users.

mdm-online:/ # su - abc
su: /bin/sh: Permission denied

mdm-online:/ # login abc
Password:
Copyright (c) 1992-2004 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
        The Regents of the University of California. All rights reserved.

FreeBSD 5.2.1-RELEASE-p9 (MDM-ONLINE) #1: Mon Jul 26 22:24:58 CEST 2004

Welcome to FreeBSD!

login: /bin/sh: No such file or directory

mdm-online:/ # ls -l /bin/sh
-r-xr-xr-x  1 root  wheel  753872 Jul 26 10:18 /bin/sh
mdm-online:/ # pw usershow abc
abc:*:1003:1003::0:0:User &:/home/abc:/bin/sh
mdm-online:/ # ls -ld /home/abc
drwxr-xr-x  2 abc  abc  512 Aug  5 09:33 /home/abc
mdm-online:/ # ls -la /home/abc
total 20
drwxr-xr-x  2 abc   abc    512 Aug  5 09:33 .
drwxr-xr-x  7 root  wheel  512 Aug  5 09:34 ..
-rw-r--r--  1 abc   abc    767 Aug  5 09:33 .cshrc
-rw-r--r--  1 abc   abc    248 Aug  5 09:33 .login
-rw-r--r--  1 abc   abc    158 Aug  5 09:33 .login_conf
-rw-------  1 abc   abc    373 Aug  5 09:33 .mail_aliases
-rw-r--r--  1 abc   abc    331 Aug  5 09:33 .mailrc
-rw-r--r--  1 abc   abc    797 Aug  5 09:33 .profile
-rw-------  1 abc   abc    276 Aug  5 09:33 .rhosts
-rw-r--r--  1 abc   abc    975 Aug  5 09:33 .shrc

I've not modified any login* file in /etc

I've no idea what's the reason, also as it worked before.
Any hints would be greatful.

Regards,
Thomas.