Subject: Re: misc/143: Setuid programs installed unreadable
To: Arne Henrik Juul <arnej@fm.unit.no>
From: Chris G. Demetriou <cgd@postgres.Berkeley.EDU>
List: netbsd-bugs
Date: 03/01/1994 17:11:16
> If the NetBSD core group takes
> (has taken?) the position that setuid binaries should be non-readable by
> default, it should be done consistently. The result of a quick grep
> through Makefiles shown below. Should I make a patch with *555 -> *111
> globally?
210 [sun-lamp] cgd % ls -l /usr/bin/tip /usr/bin/crontab /sbin/disklabel /sbin/init /sbin/shutdown
-r-xr-s--- 1 bin operator 61440 Feb 16 02:25 /sbin/disklabel*
-r-x------ 1 bin bin 118784 Feb 16 02:25 /sbin/init*
-r-sr-x--- 1 root operator 110592 Feb 16 02:26 /sbin/shutdown*
---s--x--x 1 root bin 24576 Feb 16 02:09 /usr/bin/crontab*
-r-s--x--- 1 uucp dialer 49152 Feb 16 02:11 /usr/bin/tip*
IT'S NOT A MATTER THAT SET-ID BINARIES SHOULD BE UNREADABLE,
it's that binaries that aren't executable by a given person
shouldn't be readable by the given person.
look at the above: exactly two of the binaries don't have read
permissions which 'match' their x permissions. those are
'tip' and 'crontab'. crontab is a somewhat-large security risk,
and tip, well, tip doesn't really matter because very few people
would be able to read it, even if it were g+r.
cgd
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