rlogin over trusted hosts...

Marcus J. Ranum mjr at vax2.nlm.nih.gov.nlm.nih.gov
Sun Oct 16 08:28:11 AEST 1988


In article <3043 at mipos3.intel.com> rpartha at cadev4.UUCP () writes:
>
>    I noticed a possible problem with the "rlogin" command. Typically
>    the accounts such as "sys", "news", etc. cannot be logged into since
>    their /etc/passwd entries have a "*" in the password field. But, over
>    a network it is possible to login as "sys" or "news" etc. 

	I used to change the login shells on sys, bin, etc, to something
like /usr/games/fortune, but some versions (or is it all?)(I have seen
some that don't) of rshd always execute 'rsh' commands using 'sh -c <command>'
instead of the pw->shell field in the password file.

	I don't recall if 'bin' owns the stuff in /bin anymore - used to,
but that always was a pretty open hole, if 'bin' could get onto another
system and replace /bin/sh with a trojan horse. Possibilities like that
are endless - it's better to just keep people off your network if you
don't trust 'em :-)

--mjr();



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