On 11/22/2010 10:43 AM, Les Mikesell wrote:
> On 11/22/2010 9:11 AM, Robert Moskowitz wrote:
>
>> By default, sendmail only listens on the localloop:
>>
>> DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl
>>
>> But by default to allow sendmail to even work the iptables entry is:
>>
>> -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 25 -j
>> ACCEPT
>>
>> Without this, sendmail can't even connect to localloop. But should I
>> handedit this line to something like:
>>
>> -A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp -d 127.0.0.1
>> --dport 25 -j ACCEPT
>>
>> And once you handedit iptables, you can't use the gnome firewall applet,
>> I suspect...
>>
> Every security decision has its own tradeoffs, so first you need to
> consider what you are trying to protect against. If you don't have a
> program listening on a port, it doesn't matter whether it is explicitly
> firewalled or not. A program needs root access to listen on ports below
> 1024 - and anyone with root access can change the iptables settings too...
Ah, there is the combination I missed. I was concerned about sendmail
doing what I thought it was suppose to do: only listen on loopback. If
something could change that behaviour, it could also change any iptables
settings.
I have 25 blocked on the firewall anyway. But just looking at the i(s)
and t(s). (while trying not to stuff more angels on the pinhead or some
such metaphor).
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
