Ensure outbound and established connections are configured

Information

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: 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

See Also

https://www.cisco.com/c/en/us/td/docs/security/firepower/623/configuration/guide/fpmc-config-guide-v623.html