The systems local firewall must implement a deny-all, allow-by-exception policy.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22583	GEN008540	SV-63141r1_rule		Medium

Description
A local firewall protects the system from exposing unnecessary or undocumented network services to the local enclave. If a system within the enclave is compromised, firewall protection on an individual system continues to protect it from attack.

STIG	Date
Oracle Linux 5 Security Technical Implementation Guide	2020-02-25

Details

Check Text ( C-51887r1_chk )
Check the firewall rules for a default deny rule. # iptables --list Example of a rule meeting this criteria: REJECT all -- anywhere anywhere reject-with icmp-host-prohibited A rule using DROP is also acceptable. The default rule should be the last rule of a table and match all traffic. If there is no default deny rule, this is a finding.

Fix Text (F-53729r1_fix)
Edit "/etc/sysconfig/iptables" and add a default deny rule. An example of a default deny rule: -A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited Restart the iptable service. # service iptables restart