*BSD News Article 55727


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!lll-winken.llnl.gov!uwm.edu!vixen.cso.uiuc.edu!howland.reston.ans.net!Germany.EU.net!zib-berlin.de!news.tu-chemnitz.de!irz401!uriah.heep!news
From: j@uriah.heep.sax.de (J Wunsch)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: Restricted shell in FreeBSD?
Date: 23 Nov 1995 22:25:55 GMT
Organization: Private BSD site, Dresden
Lines: 17
Message-ID: <492sdj$r6g@uriah.heep.sax.de>
References: <48dc2k$aki@maui.cc.odu.edu> <48ki66$ktk@uriah.heep.sax.de> <DIAr9y.1np@thor.shn.com>
Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch)
NNTP-Posting-Host: localhost.heep.sax.de
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
X-Newsreader: knews 0.9.3

hw@thor.shn.com (Henning Wickhorst) writes:

> But be very careful in trusting its secure promises. If the user's
> PATH includes '/bin' for example, he can execute 'sh' and he has a
> non restricted shell.

More generally, if the user has any opportunity to create an
executable on the system (run csh, drop a uuencoded binary, unpack a
tar archive, compile a C program etc.), he can quickly bypass the
restrictions.

-- 
cheers, J"org

joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)