Shell for not logging in

[Richard Tobin]

We have a user "guest" who exists for X25 file transfer purposes, with no
password.  This user's login shell was /bin/login, which was intended to
prevent any logging in on this account.  However, we recently discovered
several entries in wtmp suggesting that someone had been logged in on this
account for several hours (login normally times out after 60 seconds).

Can anyone explain this?

I have now made guest's shell be a program which immediately exits.  Can
anyone see any problems with this?

Richard Tobin,                       JANET: R.Tobin at uk.ac.ed             
AI Applications Institute,           ARPA:  R.Tobin%uk.ac.ed at nsfnet-relay.ac.uk
Edinburgh University.                UUCP:  ...!ukc!ed.ac.uk!R.Tobin