Re: Request for discussion.

Timothy Newsham (newsham@aloha.net)
Tue, 7 Feb 1995 15:53:01 -1000 (HST)

> We don't run login set-uid and have done so for quite some time.
> You need to make sure that login checks the return values of setuid()
> though, or you'll have surprising effects.  Login is usually started
> by root (from getty, ttymon, telnetd, rlogind, etc) and only seldom
> by normal users (login command in all shells).
> 
> We have not noticed any adverse side effect of this change, the positive
> effects are:
> 	- one les set-uid program
> 	- impossible to remove you remote host entry from utmp/wtmp
> 	- impossible to hide who you are with:
> 	  (login user) [subshell] follwoed by logout.

The same benefits/effects could be gotten by running login suid
but only allowing certain users (ie. the telnetd) to run it.
On systems with ACL's, like HPUX, this is trivial to do.

> Casper