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From: jbuck@epimass.EPI.COM (Joe Buck)
Newsgroups: news.admin,news.sysadmin,comp.mail.uucp
Subject: Re: Dangerous hole in Usenet!
Message-ID: <2675@epimass.EPI.COM>
Date: 27 Nov 88 07:35:31 GMT
References: <1971@van-bc.UUCP> <572@comdesign.CDI.COM> <5517@medusa.cs.purdue.edu> <561@redsox.UUCP>
Reply-To: jbuck@epimass.EPI.COM (Joe Buck)
Organization: Entropic Processing, Inc., Cupertino, CA
Lines: 22

In article <561@redsox.UUCP> campbell@redsox.UUCP (Larry Campbell) writes:
>What's all this about writing gobs of code to decipher some new shar format?
>Why not just chroot(2) to a safe place before feeding the article to sh?

The existing "uuhosts" program does this, and that's how I unpack the
maps.  It is setuid root, but reverts to the real id immediately after
the chroot(2) call, so all it can do is write to the map directory; it
cannot overwrite the copy of "sh" or "sed" in the map directory unless
root runs uuhosts (so don't have root run uuhosts!).

It is possible for a phony script to fill up the filesystem or
overwrite the maps, but that's a risk I'm willing to take (as opposed
to reading through 4Mb of map postings a month to make sure they are
safe).  Given that "uuhosts" can be obtained from comp.sources.*
archive sites, if you're worried, run it!


-- 
- Joe Buck	jbuck@epimass.epi.com, or uunet!epimass.epi.com!jbuck,
		or jbuck%epimass.epi.com@uunet.uu.net for old Arpa sites
Every day is a renewal, every morning the 
daily miracle... This joy you feel is life.	- Gertrude Stein