Information
Configure the firewall rules for new outbound, and established connections.
If rules are not in place for new outbound, and established connections all packets will be dropped by the default policy preventing network usage.
Note: Changing firewall settings while connected over network can result in being locked out of the system.
NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.
Solution
Configure iptables in accordance with site policy. The following commands will implement a policy to allow all outbound connections and all established connections:
# iptables -A OUTPUT -p tcp -m state --state NEW,ESTABLISHED -j ACCEPT
# iptables -A OUTPUT -p udp -m state --state NEW,ESTABLISHED -j ACCEPT
# iptables -A OUTPUT -p icmp -m state --state NEW,ESTABLISHED -j ACCEPT
# iptables -A INPUT -p tcp -m state --state ESTABLISHED -j ACCEPT
# iptables -A INPUT -p udp -m state --state ESTABLISHED -j ACCEPT
# iptables -A INPUT -p icmp -m state --state ESTABLISHED -j ACCEPT