SV-54918r3: The Windows Firewall with Advanced Security local connection rules must not be merged with Group Policy settings when connected to a public network. | Windows Firewall with Advanced Security Security Technical Implementation Guide

Loading benchmark…

Assessment Title

Rule Text

The Windows Firewall with Advanced Security local connection rules must not be merged with Group Policy settings when connected to a public network.

Description

Discussion Text

A firewall provides a line of defense against attack. To be effective, it must be enabled and properly configured. Local connection rules will not be merged with Group Policy settings on a public network to prevent Group Policy settings from being changed.

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-001190

References

DPMS Target Windows Firewall with Advanced Security DISA DPMS Target Windows Firewall with Advanced Security 2565

Checks

OVAL

oval:mil.disa.fso.windows:var:482200 ← xccdf_mil.disa.stig_value_public_profile_apply_local_connection_security_rules_var
oval:mil.disa.fso.windows:var:480000 ← xccdf_mil.disa.stig_value_public_profile_firewall_state_var

DISA STIG (Manual Reference)

If the system is not a member of a domain, this is NA.

If the firewall's Public Profile is not enabled (see V-17417), this requirement is also a finding.

Verify the registry value below.

If this registry value does not exist or is not configured as specified, this is a finding.

Registry Hive:  HKEY_LOCAL_MACHINE
Registry Path:  \SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile\

Value Name:  AllowLocalIPsecPolicyMerge

Type:  REG_DWORD
Value:  0x00000000 (0)

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

# Windows PowerShell
# Reconstructed from oval:mil.disa.fso.windows:def:4822
# The Windows Firewall with Advanced Security local connection rules must not be merged with Group Policy settings when connected to a public network.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile!AllowLocalIPsecPolicyMerge value equals variable
# registry_object (registry_test)
function test_1 {
  return (((@{String='reg_sz';ExpandString='reg_expand_sz';Binary='reg_binary';DWord='reg_dword';MultiString='reg_multi_sz';QWord='reg_qword';None='reg_none'}[(Get-Item -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile').GetValueKind('AllowLocalIPsecPolicyMerge').ToString()]) -eq 'reg_dword') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile' -Name 'AllowLocalIPsecPolicyMerge' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'AllowLocalIPsecPolicyMerge') -eq 0))
}
# System is not a member of a domain
# registry_object (registry_test)
function test_2 {
  return (((@{String='reg_sz';ExpandString='reg_expand_sz';Binary='reg_binary';DWord='reg_dword';MultiString='reg_multi_sz';QWord='reg_qword';None='reg_none'}[(Get-Item -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\TCPIP\Parameters').GetValueKind('Domain').ToString()]) -eq 'reg_sz') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\TCPIP\Parameters' -Name 'Domain' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'Domain') -eq ''))
}
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile!EnableFirewall value equals variable
# registry_object (registry_test)
function test_3 {
  return (((@{String='reg_sz';ExpandString='reg_expand_sz';Binary='reg_binary';DWord='reg_dword';MultiString='reg_multi_sz';QWord='reg_qword';None='reg_none'}[(Get-Item -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile').GetValueKind('EnableFirewall').ToString()]) -eq 'reg_dword') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile' -Name 'EnableFirewall' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'EnableFirewall') -eq 1))
}
# HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile!EnableFirewall non existent
# registry_object (registry_test)
function test_4 {
  return (-not ($null -ne (Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile' -Name 'EnableFirewall')))
}
# HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\PublicProfile!EnableFirewall value equals variable
# registry_object (registry_test)
function test_5 {
  return (((@{String='reg_sz';ExpandString='reg_expand_sz';Binary='reg_binary';DWord='reg_dword';MultiString='reg_multi_sz';QWord='reg_qword';None='reg_none'}[(Get-Item -Path 'Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\PublicProfile').GetValueKind('EnableFirewall').ToString()]) -eq 'reg_dword') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\PublicProfile' -Name 'EnableFirewall' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'EnableFirewall') -eq 1))
}

if (-not (((test_1 -or test_2) -and (test_3 -or -not ((test_4 -and test_5)))))) {
  Write-Output "PASS"
} else {
  Write-Output "FAIL"
}

Assessment Script Powered by AISyntax-verified

A standalone PowerShell script to assess this control automatically. Review before running it in your environment.

Syntax-checked as valid PowerShell. Not executed here — running it for real needs the actual windows_firewall target this check assesses.

# OVAL Definition: oval:mil.disa.fso.windows:def:4822
$domainCheck = Test-Path -Path "HKLM:\System\CurrentControlSet\Services\TCPIP\Parameters\Domain"
if ($domainCheck) {exit 1}
$firewallMerge = Get-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\WindowsFirewall\PublicProfile" -ErrorAction SilentlyContinue
if ($firewallMerge -eq $null) {exit 0}
if ($firewallMerge.AllowLocalIPsecPolicyMerge -eq 0) {exit 0}
exit 1

Remediation

If the system is not a member of a domain, this is NA.

Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Windows Firewall with Advanced Security -> Windows Firewall with Advanced Security -> Windows Firewall Properties (this link will be in the right pane) -> Public Profile Tab -> Settings (select Customize) -> Rule merging, "Apply local connection security rules:" to "No".