Re: [Exim] Does Exim have security problems?

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Author: Exim Users Mailing List
Date:  
To: Phil Pennock
CC: Exim Users Mailing List
Subject: Re: [Exim] Does Exim have security problems?
[ On Tuesday, September 5, 2000 at 22:07:29 (+0200), Phil Pennock wrote: ]
> Subject: Re: [Exim] Does Exim have security problems?
>
> On 2000-09-05 at 15:52 -0400, Greg A. Woods gifted us with:
> > Such sensitive information can just as easily live in another separate
> > configuration file read only by the filtering software itself and thus
> > even exim can't be directly tricked into revealing its contents to your
> > users.
>
> See <http://www.exim.org/exim-html-3.10/doc/html/filter.html>


hmmm... yes... that. Not being a full-time exim user I tend to forget
about "esoteric" features like that. Personally I'd much rather put the
filtering, classification, and collating features in the final delivery
agent, and though lots of people consider procmail or deliver to be
answers to this problem I consider them to be a worse problem so I'd
rather choose something like Cyrus Sieve:

    <URL:http://www.cyrusoft.com/sieve/>


I suppose even Sieve could be built into the MTA, but I think it's safer
and cleaner to keep it separate, and in the face of a mailer that's got
such good debugging and tracing support, more sucure from the user's
point of view too!

> Mind, I partially agree. One of my system's users uses Exim's extended
> syntax for .forward files, and I can see an uncomfortably large amount
> of information about his mailing-lists via my cron-job'd eximstats.


and what if you turn on all debugging, tracing, and verbose message
options and then do a non-delivery test to a mailbox that happens to be
controlled by a .forward file. I'd be that with very little
experimentation all but the semantically neutral information in that
user's .forward file will be revealed.

-- 
                            Greg A. Woods


+1 416 218-0098      VE3TCP      <gwoods@???>      <robohack!woods>
Planix, Inc. <woods@???>; Secrets of the Weird <woods@???>