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From: campbell@maynard.UUCP (Larry Campbell)
Newsgroups: net.news,net.wanted.sources
Subject: Re: Shar format found dangerous
Message-ID: <288@maynard.UUCP>
Date: Sun, 27-Apr-86 10:33:18 EDT
Article-I.D.: maynard.288
Posted: Sun Apr 27 10:33:18 1986
Date-Received: Mon, 28-Apr-86 22:04:58 EDT
References: <424@bu-cs.UUCP>
Organization: The Boston Software Works Inc., Maynard, MA
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Xref: linus net.news:3946 net.wanted.sources:2243

> A thought on making un-shar'ing safer:
> 
> Obviously making a chroot'd account with a private bin, usr/bin and
> usr/ucb (if applicable) would make this much, much safer. One could
> also carefully limit the commands (is there any good reason for an
> unshar to ever do an 'rm'? you could put 'rm' somewhere else for use
> within this account.) ...
> 	-Barry Shein, Boston University

This code already exists, I think...  "uuhosts" comes with a program
called "mapsh" that chroots to a specified directory and then execs an
arbitrary program.  You just need to pipe the shar archive into a
"mapsh /bin/sh".  All we need is to standardize on what set of
programs need to be available to shar scripts (many sites don't have
the disk space to have two copies of everything in /usr/bin, and you
*don't* want to use links for obvious reasons).
-- 
Larry Campbell                                 The Boston Software Works, Inc.
ARPA: maynard.UUCP:campbell@harvard.ARPA       120 Fulton Street
UUCP: {harvard,cbosgd}!wjh12!maynard!campbell  Boston MA 02109