Re: Local delivery problems on FreeBSD

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Author: Philip Hazel
Date:  
To: Mark Murray
CC: Chris Thompson, exim-users
Subject: Re: Local delivery problems on FreeBSD
On Fri, 29 Nov 1996, Mark Murray wrote:

> this is too easy for the casual cracker/crasher:


Indeed. But such a cracker/crasher has to have an account on your
system. You should have control over such a person. There are plenty of
ways such people can bring your system to its knees, e.g. write a
"rabbit" program that spawns zillions of looping subprocesses that spawn
zillions of looping subprocesses that...

If anyone did this

> #!/bin/sh
> cd /var/mail  #...where /var/mail is mode 1777
> for i in `awk -F: '{print $1}' /etc/passwd` ; do
>    touch $i
> done

>
> ...and let the poor mail administrator sort out the mess and full
> mail spool when he gets back in on Monday.


on one of our systems, the mail administrator would subsequently apply
severe disciplinary procedures to the culprit and then release him or
her to the baying crowd of 5,999 other users whose mail was blocked for
the weekend.

We do have problems with students, but peer pressure is a great control.

--
Philip Hazel                   University Computing Service,
ph10@???             New Museums Site, Cambridge CB2 3QG,
P.Hazel@???          England.  Phone: +44 1223 334714