[ale] firewalls on cd

Tue Dec 18 16:36:06 EST 2001

Coyote Linux is pretty kewl.  It is designed to run from a floppy, but you
could probably hack it to run from a CD, but don't see why you'd want to do
that... just keep backups of your boot disk and firewall scripts, and you'll
be fine.

Charles

> -----Original Message-----
> From: John Wells [mailto:jbwellsiv at yahoo.com]
> Sent: Tuesday, December 18, 2001 4:19 PM
> To: Ale at ale.org
> Subject: [ale] firewalls on cd (was [ale] unidentified processes)
>
>
> Dow,
>
> Thanks for your reply, and for everyone who has helped
> on my first iptables outing.
>
> Running a bootable CD sounds like a great idea...and
> there seems to be quite a few options out there.  Does
> anyone have recommendations on which to use?  I've run
> across Sentry Firewall CD...what others are available?
>
> Thanks,
> John
>
>
> --- Dow Hurst <dhurst at kennesaw.edu> wrote:
> > John,
> > Even though James email is funny, he is absolutely
> > correct in the
> > approach.  The portmapper and rpc.statd are RPC
> > based processes along
> > with NFS and NIS (RPC uses UDP traditionally instead
> > of TCP
> > connections).  The portmapper advertises what RPC
> > services are available
> > on particular ports to remote requests.  rpc.statd
> > lets remote
> > applications and remoted machines "know" what the
> > status, of the local
> > machine or application that is RPC enabled, is.
> > Both services are
> > easily spoofed, cracked, and known cracks are
> > available for both.  Since
> > you have had those running, as well as ftpd, you
> > should reload from
> > scratch and choose to format your partitions too.
> > This is faster and
> > less prone to mistakes than working thru proving the
> > machine is clean.
> > (Even though that would be very educational!)  No
> > service should be run
> > directly on a firewall machine that doesn't have to
> > be.  That is why it
> > is recommended that you have a server inside your
> > network for services
> > like Samba, NFS, and appletalk and not combine your
> > firewall server with
> > that machine.  Running your firewall from a CD
> > filesystem is a beautiful
> > suggestion.  Your cracker is limited even more by
> > not being able to
> > change the read only system.  I need to look into
> > that!
> >
> > One major difficulty in setting up a firewall for
> > people not intimate
> > with Linux, or any OS that is used, is that default
> > choices during
> > install can leave you quite vulnerable and your not
> > even aware of it til
> > you learn more.  Use "netstat -an" to prove that you
> > have *only* sshd
> > advertising a service on port 22 before you hook
> > back up to the
> > Internet.  You don't even have to have that, except
> > it is convenient and
> > secure for remote admin.
> >
> > Here is an excerpt from an email Bob sent me just
> > the other day:
> > "Btw, we just put up the first of 4 firewalls at
> > this client (in
> > Europe).
> > It took only one hour and 34 minutes for someone to
> > discover it and
> > start
> > breaking into it.  Within 20 minutes after that, a
> > second cracker joined
> > in."
> >
> > So you see it doesn't take long for a scan to find
> > you and start to
> > reveal possible entry points.  I would just reload
> > to be on the safe
> > side.  With more experience and a good "dd" backup,
> > you can quickly
> > identify differences in a file system to see if your
> > hacked.  At my
> > workplace, we have been recovering from a several
> > crackers for the past
> > year.  Nov. 2000 we had the telnetd hole exploited
> > on most of our SGIs.
> > We don't have much manpower to rebuild systems and
> > keep our work moving
> > along, so it has taken all year to work on
> > rebuilding machines.  Hope
> > this helps,
> > Dow
> >
> >
> > John Wells wrote:
> > >
> > > In addition to ftp and ssh, I have two processes
> > > running on ports 111 and 1024.  They both seem to
> > work
> > > with rpc, and are the portmapper and rpc.statd
> > > respectively.
> > >
> > > Can I disable these processes without any effect
> > to my
> > > system?  If so, I assume I just remove the links
> > to
> > > the startup scripts from my runlevel's startup
> > > directory.
> > >
> > > Also, how insecure is it to run ftp on my
> > > router/firewall box?
> > >
> > > Thanks,
> > > John
> > >
> > > __________________________________________________
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> > > ---
> > > This message has been sent through the ALE general
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> >
> > --
> >
> __________________________________________________________
> > Dow Hurst                   Office: 770-499-3428
> > Systems Support Specialist  Fax:    770-423-6744
> > 1000 Chastain Rd.
> > Chemistry Department SC428
> > Email:dhurst at kennesaw.edu
> > Kennesaw State University
> > Dow.Hurst at mindspring.com
> > Kennesaw, GA 30144
> > *********************************
> > *Computational Chemistry is fun!*
> > *********************************
> >
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>
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>

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