From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michael Tremer <michael.tremer@ipfire.org>
To: development@lists.ipfire.org
Subject: Re: [PATCH] firewall: Accept traffic on loopback interface if source
 and destination are within 127.0.0.0/8 only
Date: Tue, 19 May 2020 09:20:28 +0100
Message-ID: <166B06A6-A5A1-4E69-8277-B21690ED842F@ipfire.org>
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Okay, thanks for testing this.

I will ask Arne to revert it.

-Michael

> On 18 May 2020, at 22:03, Matthias Fischer <matthias.fischer(a)ipfire.org> =
wrote:
>=20
> Hi,
>=20
> perhaps its only me, but after applying this patch for testing purposes
> I don't see any (redirected) urlfilter block pages anymore.
>=20
> Only the firewall logs are telling me:
>=20
> ...
> REJECT_INPUT lo TCP 192.168.100.254 53464 192.168.100.254 81
> ...
>=20
> I had to build a new "Incoming Firewall Access" rule (INPUTFW) allowing
> TCP traffic from (e.g.) 192.168.100.254/32 to GREEN (192.168.100.254) to
> TCP port 81 to see a block page again...
>=20
> Only me?
>=20
> Best,
> Matthias
>=20
> On 14.05.2020 12:36, Michael Tremer wrote:
>> Hello,
>>=20
>> This is indeed *very* unlikely, but I am okay with this patch being accept=
ed.
>>=20
>> Acked-by: Michael Tremer <michael.tremer(a)ipfire.org>
>>=20
>> Best,
>> -Michael
>>=20
>>> On 13 May 2020, at 21:21, Peter M=C3=BCller <peter.mueller(a)ipfire.org> =
wrote:
>>>=20
>>> This ensures traffic on the loopback interface matches the IPv4
>>> loopback characteristics (source and destination are within 127.0.0.0/8)
>>> and prevents any damage in the unlikely case of non-loopback traffic
>>> being injected/emitted (in)to the loopback interface.
>>>=20
>>> Cc: Arne Fitzenreiter <arne.fitzenreiter(a)ipfire.org>
>>> Cc: Michael Tremer <michael.tremer(a)ipfire.org>
>>> Signed-off-by: Peter M=C3=BCller <peter.mueller(a)ipfire.org>
>>> ---
>>> src/initscripts/system/firewall | 6 +++---
>>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>>=20
>>> diff --git a/src/initscripts/system/firewall b/src/initscripts/system/fir=
ewall
>>> index 00512d9fa..409aaf7a9 100644
>>> --- a/src/initscripts/system/firewall
>>> +++ b/src/initscripts/system/firewall
>>> @@ -219,10 +219,10 @@ iptables_init() {
>>> 	iptables -A INPUT -j ICMPINPUT
>>> 	iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
>>>=20
>>> -	# Accept everything on loopback
>>> +	# Accept everything on loopback if both source and destination are with=
in 127.0.0.0/8
>>> 	iptables -N LOOPBACK
>>> -	iptables -A LOOPBACK -i lo -j ACCEPT
>>> -	iptables -A LOOPBACK -o lo -j ACCEPT
>>> +	iptables -A LOOPBACK -i lo -s 127.0.0.0/8 -d 127.0.0.0/8 -j ACCEPT
>>> +	iptables -A LOOPBACK -o lo -s 127.0.0.0/8 -d 127.0.0.0/8 -j ACCEPT
>>>=20
>>> 	# Filter all packets with loopback addresses on non-loopback interfaces.
>>> 	iptables -A LOOPBACK -s 127.0.0.0/8 -j DROP
>>> --=20
>>> 2.26.1
>>=20
>=20


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