The macOS Application Firewall must be enabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-81681	AOSX-13-001080	SV-96395r1_rule		Medium

Description
The Application Firewall is the built-in firewall that comes with macOS and must be enabled. Firewalls protect computers from network attacks by blocking or limiting access to open network ports. Application firewalls limit which applications are allowed to communicate over the network.

STIG	Date
Apple OS X 10.13 Security Technical Implementation Guide	2020-05-29

Details

Check Text ( C-81457r1_chk )
If an approved HBSS solution is installed, this is not applicable. To check if the macOS firewall has been enabled, run the following command: /usr/bin/sudo /usr/libexec/ApplicationFirewall/socketfilterfw --getglobalstate If the result is "disabled", this is a finding.

Fix Text (F-88529r1_fix)
To enable the firewall, run the following command: /usr/bin/sudo /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate on