Re: UFW logging

kalinix <[email protected]> Fri, 23 Dec 2011 02:38:49 +0200
Newsgroups org.kernel.vger.linux-admin
Message-ID <[email protected]>

On Thu, 2011-12-22 at 21:28 +0530, Saurabh Bathe wrote: 
> On Tuesday 20 December 2011 07:33 PM, Dermot Paikkos wrote:
> > Chain ufw-user-limit (0 references)
> >      pkts      bytes target     prot opt in     out     source
> >       destination
> >         0        0 LOG        all  --  *      *       0.0.0.0/0
> >     0.0.0.0/0           limit: avg 3/min burst 5 LOG flags 0 level 4
> > prefix `[UFW LIMIT BLOCK] '
> 
> I would say the rule above *could* be suspect, which would log anything 
> that it catches. Depending on where in the filter it is being 
> referenced, it maybe catching those packets. I cannot say definitively 
> without actually seeing whole iptables -nL output.
> 
> Thanks,
> Saurabh
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It's not blocked, it's limited to 3 packets per minute, with a burst to
5. Only when this limit is reached the connection is blocked and the
event is logged with the [UFW LIMIT BLOCK]. So you may want to check
your syslog (or whatever logging system you are using) for this prefix.
While this doesn't prevent users to connect to your server, it can
affect the legit traffic.

What you need is an IDS (either ModSecurity for apache [1] and/or ossec
[2] - but hey, a strong tweaking is necessary for both of them in order
to work as desired - you have been warned :) )



[1] http://www.modsecurity.org/
[2] http://www.ossec.net/

P.S. there is a good howto for mod_security on Ubuntu (I presume you are
using Ubuntu) here:
http://blog.bodhizazen.net/linux/how-to-mod_security-ubuntu-904/

HTH

-- 


Calin

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