From: /dev/rob0 <rob0@gmx.co.uk>
To: netfilter@vger.kernel.org
Subject: Re: Possible bug in iptables : -m --uid-owner not working with ping
Date: Mon, 22 Oct 2012 09:44:58 -0500 [thread overview]
Message-ID: <20121022144458.GC3672@harrier.slackbuilds.org> (raw)
In-Reply-To: <50855A6B.1070000@lavabit.com>
On Mon, Oct 22, 2012 at 04:38:35PM +0200, matja¸ wrote:
> Is it possible that owner matching does not work correctly ?
> I tried blocking internet access to one user, but found out he can
> still use ping.
ping(1) must be SUID to have the privilege to make ICMP echo request
packets. Therefore outgoing pings are done as root.
Your solution would be to change permissions of your ping binary such
that the user in question cannot execute it.
snip
> Also : the -match --uid-owner seems to work on other protocols.
Indeed.
> Oddly enough, using group id instead seems to work :
snip
> Is this expected behaviour ?
Yes.
--
http://rob0.nodns4.us/ -- system administration and consulting
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prev parent reply other threads:[~2012-10-22 14:44 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-22 14:38 Possible bug in iptables : -m --uid-owner not working with ping matjaž
2012-10-22 14:43 ` AW: " Steffen Heil (Mailinglisten)
2012-10-22 16:19 ` Jan Engelhardt
2012-10-22 18:56 ` matjaž
2012-10-22 14:44 ` Eric Leblond
2012-10-22 14:44 ` /dev/rob0 [this message]
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