CIS ISO NIST CSF SOC

Firewall is on and configured

How to enable Firewall and Stealth mode

Open System Preferences, click Network, then Firewall.
Toggle Turn On Firewall.
Click Options..., scroll to the bottom, and toggle Enable stealth mode.

How to enable on Monterey and older

Open System Preferences, click Security & Privacy, then the tab Firewall.
Click the lock icon in the bottom-left, then enter the account password.
Click Turn On Firewall.
Click Firewall Options... and then Enable stealth mode.

If you are unable to enable the firewall using System Preferences, try the Terminal commands described below.

How to reset Firewall from Terminal

Open Terminal.
Disable stealth mode: /usr/libexec/ApplicationFirewall/socketfilterfw --setstealthmode off
Disable the firewall: /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate off
Re-enable the firewall: /usr/libexec/ApplicationFirewall/socketfilterfw --setglobalstate on
Re-enable stealth mode: /usr/libexec/ApplicationFirewall/socketfilterfw --setstealthmode on
Check current firewall status: /usr/libexec/ApplicationFirewall/socketfilterfw --getglobalstate
Check stealth mode status: /usr/libexec/ApplicationFirewall/socketfilterfw --getstealthmode

Time to fix

< 1m

What

Firewall prevents contact from other computers on the Internet or on your network. Learn more on the Apple Support page.

What if I use other firewalls?

You should have the system firewall enabled because other firewalls cannot support stealth mode. Stealth mode is necessary if you are directly connected to the internet via a hotspot or without a router, for example. Stealth mode prevents your Mac from being discovered by threat actors scanning the internet for devices.