Hey,

Could you dump the generated iptables ruleset?

I do not see anything that could potentially be a problem here that is causing your behaviour:

  https://git.ipfire.org/?p=ipfire-2.x.git;a=blob;f=config/firewall/firewall-policy;h=078c3c515c31f1f385a2159f83fb5c6c52f5e89f;hb=HEAD

-Michael

> On 15 Dec 2018, at 16:36, Peter Müller <peter.mueller(a)link38.eu> wrote:
> 
> Hello list,
> 
> I recently stumbled across a strange behaviour of IPFire 2.x, which
> seems to be quite critical in my eyes, but I am not sure whether it is
> intentional or not.
> 
> Default settings of IPFire allow traffic from internal networks
> (GREEN, BLUE, ORANGE) to the internet (RED), as documented here:
> https://wiki.ipfire.org/configuration/firewall/default-policy
> 
> For several reasons, no direct internet access is desired on most
> firewall installations I administer, so setting the "default firewall
> behaviour" to DROP for both FORWARD and OUTGOING usually is one of
> the first steps after installation.
> 
> Speaking about GREEN and BLUE, this seems to work: No direct connection
> is possible except it has been explicitly allowed.
> 
> It turns out this setting does not apply to traffic from ORANGE: Even
> default is set to DROP, and no firewall rules allowing anything are
> in place, a server located in DMZ is able to reach full internet -
> every port on every IP in every country.
> 
> This is not my expectation of "default policy" = DROP after all!
> 
> Could somebody of the core developers urgently have a look at this, please?
> 
> Thanks, and best regards,
> Peter Müller
> -- 
> Microsoft DNS service terminates abnormally when it recieves a response
> to a DNS query that was never made.  Fix Information: Run your DNS
> service on a different platform.
> 		-- bugtraq