Xref: utzoo unix-pc.general:331 comp.sys.att:2472
Path: utzoo!utgpu!water!watmath!clyde!mtune!shlepper!andys
From: andys@shlepper.ATT.COM (a.b.sherman)
Newsgroups: unix-pc.general,comp.sys.att
Subject: Re: Major security problem in the UA: looking for a real fix
Summary: Leave your nose alone.  Don't cut it off to spite your face.
Keywords: UNIX PC, UA, security hole
Message-ID: <184@shlepper.ATT.COM>
Date: 13 Feb 88 20:22:37 GMT
References: <1023@woton.UUCP> <2017@bsu-cs.UUCP> <118@bergy.UUCP> <114@hodge.UUCP>
Organization: AT&T Bell Laboratories, Middletown, NJ
Lines: 30

In article <114@hodge.UUCP>, rusty@hodge.UUCP (Rusty Hodge) writes:
> [Description of several well known holes in the UA]
> 
> Let's face it: the UA is *evil*.  Get rid of it.  Hide it in a nested directory
> and take away its execute privledges.  Make it go away.
> 
> Root will still be able to get to most of those nifty UA-run programs for
> screen-oriented system administration. :->


But what if you like the convenience of the UA and multiple windows? 
There is a better way.  The nasty piece of goods is a program called
uasetx which resides in /usr/lib/ua.  This is the guy who does a setuid
to root for those things in the UA which are exec'ed that way.  Here's
what you do.  Create a group called "super" or some such.  Give uasetx
group execute permissions for super and no others.  Put yourself,
(assuming you own the machine), install, and anyone you'd trust with
your livelihood in group super.  Change the group id for those logins in
/etc/passwd and your in business.  Presto. You have left everyone the
convenience of the UA, left yourself the convenience of the dangerous
stuff in the UA, and controlled access to those same functions.  I hear
that floppies can be a problem for your un-super user, but you can
always access the floppy drive from a shell, or hack the UA files to not
require root privileges to write to the floppy.  Now then, doesn't your
face look better with the nose still on it??
-- 
Andy Sherman / AT&T Bell Laboratories (Medical Diagnostic Systems)
480 Red Hill Road / Middletown NJ 07748 / (201) 615-5708
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