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Date:      Mon, 08 Sep 1997 21:45:26 +0100
From:      Brian Somers <brian@awfulhak.org>
To:        "Rodney W. Grimes" <rgrimes@GndRsh.aac.dev.com>
Cc:        nate@mt.sri.com (Nate Williams), brian@awfulhak.org, freebsd-stable@freebsd.org
Subject:   Re: Don Croyle: make world failing at ppp install (again) 
Message-ID:  <199709082045.VAA04570@awfulhak.demon.co.uk>
In-Reply-To: Your message of "Mon, 08 Sep 1997 00:28:39 PDT." <199709080728.AAA16253@GndRsh.aac.dev.com> 

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> You can wave your hands all around about ease of use vs doing it
> right, but the bottom line is as ppp stands today it is a security
> hole, and security holes are bad karma.
> 
> Okay the group network cuts down the exposure, no you only have to deal
> with a fist full of users who can bring your router down.
> 
> I simply fix most of the problem by rm'ing the user land ppp files,
> use the kernel version, make sure I don't have any tun drivers, etc.

This is getting silly !  Now, by default, *nobody* except root can 
run ppp, PERIOD.

If an admin chooses to make someone a member of group network, they'd 
better make sure that said user can't access the ppp config files.

Now, please, where's the hole ?

> > > Running ppp does _NOT_ *requires* write access to the routing table,
> > > this is much much much better handled by properly configuring
> > > a real routing daemon and running real routing protocols.
> > 
> > Bzzt, thanks for playing, but for 99.9999999% of the folks who run a PPP
> > connection, a 'real routing daemon' is way overkill and will cause them
> > no-end of headaches.  
> 
> And for those 99.9999% of the folks /sbin/routed -q will do just what
> they need.  Now was that so hard.  I didn't say the only real routing
> daemon was gated, but for server side ppp boxes it's a lot more guttsy
> than /sbin/routed.  If you have VLSM run routed in ripv2 mode.

But Nate & others are pointing out that most users don't want a 
routing daemon at all.  They have a routing table with a loopback 
from ifconfig'ing lo0, a ppp route from ifconfig'ing tun0 and a 
default down that tun route.

A large chunk of these users also have a LAN with another route 
that's the result of their ifconfig.

No routing daemon is required - I'd nearly vote for disabling 
routed -q for this reason.

> > 
> > > Infact I have to go to great pains to _stop_ what ppp tries to do to
> > > the routing tables, gated handles it MUCH better!
> > 
> > Gated handles nothing better unless you've got a spare 40 hours to
> > dedicate to figuring out how it works.  Gated is only necessary if
> > you've got multiple 'routes', and most (see above) folks have a single
> > network connection which is their PPP link.
> > 
> > Engineering is finding the best solution for most folks, optimizing it
> > for it while trying to not penalize the rest of the folks.  What ijppp
> > does is take the engineering approach, and not find the 'best/most
> > complicated/gated' solution.
> 
> And leaves a big security hole....

Not if you don't make it yourself - if you want incoming sessions, 
use PAP/CHAP and *never* make anyone a member of group network.

> -- 
> Rod Grimes                                      rgrimes@gndrsh.aac.dev.com
> Accurate Automation, Inc.                   Reliable computers for FreeBSD

-- 
Brian <brian@awfulhak.org>, <brian@freebsd.org>
      <http://www.awfulhak.org>;
Don't _EVER_ lose your sense of humour....





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