Path: utzoo!attcan!uunet!mcvax!hp4nl!botter!star.cs.vu.nl!maart
From: maart@cs.vu.nl (Maarten Litmaath)
Newsgroups: comp.unix.wizards
Subject: Re: Secure setuid shell scripts
Message-ID: <1582@solo5.cs.vu.nl>
Date: 27 Oct 88 13:41:05 GMT
References: <14069@mimsy.UUCP> <307@lakart.UUCP>
Reply-To: maart@cs.vu.nl (Maarten Litmaath)
Organization: VU Informatica, Amsterdam
Lines: 19

In article <307@lakart.UUCP> dg@lakart.UUCP (David Goodenough) writes:
\...
\#! /bin/sh -
\...
\This closes up the security hole very nicely here (unless there's some
\sneaky way of getting in that I didn't know about).

There's still another way (keyword: race condition).
BTW, our 4.3BSD /bin/sh doesn't stop searching for flags after the `-'.

\Incidentally, lakart
\is BSD4.3, so we DO have symbolic links: it was suggested that if no
\symbolic links existed, then by denying write permission to general users
\on all filesystems where suid 0 reside the problem could be reduced.

That's correct, but a bit inconvenient: no setuid scripts on /usr (/usr/tmp).
-- 
George Bush:                          |Maarten Litmaath @ VU Amsterdam:
             Capt. Slip of the Tongue |maart@cs.vu.nl, mcvax!botter!maart