core-agent-linux/network/iptables
Pawel Marczewski 63d8065e4f
firewall: drop INVALID state TCP packets
Packets detected as INVALID are ignored by NAT, so if they are not
dropped, packets with internal source IPs can leak to the outside
network.

See:

https://bugzilla.netfilter.org/show_bug.cgi?id=693
http://www.smythies.com/~doug/network/iptables_notes/

Fixes QubesOS/qubes-issues#5596.
2020-01-24 19:01:00 +01:00

44 lines
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# Generated by iptables-save v1.4.5 on Mon Sep 6 08:57:46 2010
*nat
:PREROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:PR-QBS - [0:0]
:PR-QBS-SERVICES - [0:0]
-A PREROUTING -j PR-QBS
-A PREROUTING -j PR-QBS-SERVICES
-A POSTROUTING -o vif+ -j ACCEPT
-A POSTROUTING -o lo -j ACCEPT
-A POSTROUTING -j MASQUERADE
COMMIT
*raw
:QBS-PREROUTING - [0:0]
-A PREROUTING -j QBS-PREROUTING
COMMIT
*mangle
:QBS-POSTROUTING - [0:0]
-A POSTROUTING -j QBS-POSTROUTING
COMMIT
# Completed on Mon Sep 6 08:57:46 2010
# Generated by iptables-save v1.4.5 on Mon Sep 6 08:57:46 2010
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
:QBS-FORWARD - [0:0]
-A INPUT -m state --state INVALID -j DROP
-A INPUT -i vif+ -p udp -m udp --dport 68 -j DROP
-A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i vif+ -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -i vif+ -j REJECT --reject-with icmp-host-prohibited
-A INPUT -j DROP
-A FORWARD -m state --state INVALID -j DROP
-A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -j QBS-FORWARD
-A FORWARD -i vif+ -o vif+ -j DROP
-A FORWARD -i vif+ -j ACCEPT
-A FORWARD -j DROP
COMMIT
# Completed on Mon Sep 6 08:57:46 2010