On Wed, Sep 04, 2002 at 06:05:52PM +0800, Ian Perez wrote:
> > Hi! can anyone tell me how to close the ff port. i did an nmap and this
> > came up:
> >
> > 32774/tcp  open        sometimes-rpc11
> >
> > looks like trouble :)
>
> netfilter?
> 
> iptables -A INPUT -s 0/0 -p TCP --dport 32774 -j DROP
> 
> or
> 
> ipchains -A input -s 0/0 -p TCP -d 32774 -j REJECT

Uhh... not quite perfect, IMHO. Go to the root of the problem, and shut
down the daemon if it's not needed. If it has to stay up, but should not
be accessible to the outside world, that's the only time you do "crutch
work" using the firewall software. See Ian Sison's post[1] for more
details.

[1] 
http://marc.free.net.ph/message/Pine.LNX.4.33L2.0208312323250.21850-100000%40jeprox.qsr.com.ph.html

To find out which process is listening on port 32774:

    # netstat -lnp | grep 32774

Find out what it is. It's probably related to NFS, and if my memory
serves me right, the port number changes on every daemon reload.
Hopefully this program understands tcpwrappers, in which case
/etc/hosts.{allow,deny} should tell it whether or not to entertain
messages from outside.

What I've found to help, aside from this fundamental task of only
running secure daemons and running them properly configured, is to use
IPTables (or probably ipchains) to do a deny-by-default. Documentation
on this exist in the netfilter site. This allows me to cover up for
daemons that change ports on every reload, especially those related to
NFS, only having open the ports that I know I need to keep open.

I can't go without stressing that each of these (reachable-from-outside)
programs must be checked regularly to ensure that they do not have
unpatched known exploits.

 --> Jijo

-- 
Federico Sevilla III   :  http://jijo.free.net.ph
Network Administrator  :  The Leather Collection, Inc.
GnuPG Key ID           :  0x93B746BE
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