MacOS ALF is misconfigured

AnalysisType: rule
Filename: osquery_mac_application_firewall.py
RuleID: "Osquery.Mac.ApplicationFirewallSettings"
DisplayName: "MacOS ALF is misconfigured"
Enabled: true
LogTypes:
  - Osquery.Differential
Tags:
  - Osquery
  - MacOS
  - Security Control
  - Defense Evasion:Impair Defenses
Reports:
  CIS:
    - 2.6.3
    - 2.6.4
  MITRE ATT&CK:
    - TA0005:T1562
Severity: High
Description: >
  The application level firewall blocks unwanted network connections made to your
  computer from other computers on your network.
Runbook: Re-enable the firewall manually or with configuration management
Reference: https://support.apple.com/en-us/HT201642
SummaryAttributes:
  - name
  - hostIdentifier
  - action
Tests:
  - Name: ALF Disabled
    ExpectedResult: true
    Log:
      {
        "name": "pack_incident-response_alf",
        "action": "added",
        "hostIdentifier": "test-host",
        "columns":
          {
            "logging_enabled": "0",
            "stealth_enabled": "0",
            "firewall_unload": "0",
            "allow_signed_enabled": "0",
            "global_state": "0",
            "logging_option": "0",
            "version": "1.6",
          },
      }
  - Name: ALF Enabled
    ExpectedResult: false
    Log:
      {
        "name": "pack_incident-response_alf",
        "action": "added",
        "hostIdentifier": "test-host",
        "columns":
          {
            "logging_enabled": "1",
            "stealth_enabled": "1",
            "firewall_unload": "0",
            "allow_signed_enabled": "1",
            "global_state": "1",
            "logging_option": "0",
            "version": "1.6",
          },
      }


# ------ paired body: osquery_mac_application_firewall.py ------

QUERIES = {"pack_incident-response_alf", "pack/mac-cis/ApplicationFirewall"}


def rule(event):
    if event.get("name") not in QUERIES:
        return False

    if event.get("action") != "added":
        return False

    return (
        # 0 If the firewall is disabled
        # 1 If the firewall is enabled with exceptions
        # 2 If the firewall is configured to block all incoming connections
        int(event.deep_get("columns", "global_state")) == 0
        or
        # Stealth mode is a best practice to avoid responding to unsolicited probes
        int(event.deep_get("columns", "stealth_enabled")) == 0
    )


def title(event):
    return f"MacOS firewall disabled on [{event.get('hostIdentifier')}]"