Configure validation of ROCA-vulnerable WHfB keys during authentication
Verified with Windows 11 25H2 — updated on July 30, 2026
Supported on: At least Windows Vista
Path in the GPO console
Computer Configuration\Administrative Templates\System\Security Account Manager Description
This policy setting allows you to configure how domain controllers handle Windows Hello for Business (WHfB) keys that are vulnerable to the "Return of Coppersmith's attack" (ROCA) vulnerability. For more information on the ROCA vulnerability, please see: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-15361 https://en.wikipedia.org/wiki/ROCA_vulnerability If you enable this policy setting the following options are supported: Ignore: during authentication the domain controller will not probe any WHfB keys for the ROCA vulnerability. Audit: during authentication the domain controller will emit audit events for WHfB keys that are subject to the ROCA vulnerability (authentications will still succeed). Block: during authentication the domain controller will block the use of WHfB keys that are subject to the ROCA vulnerability (authentications will fail). This setting only takes effect on domain controllers. If not configured, domain controllers will default to using their local configuration. The default local configuration is Audit. A reboot is not required for changes to this setting to take effect. Note: to avoid unexpected disruptions this setting should not be set to Block until appropriate mitigations have been performed, for example patching of vulnerable TPMs. More information is available at https://go.microsoft.com/fwlink/?linkid=2116430.
Registry
Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM MDM / Intune (CSP)
./Device/Vendor/MSFT/Policy/Config/ADMX_sam/SamNGCKeyROCAValidation Microsoft Learn documentation Mapping data: Microsoft Learn (CC BY 4.0)
Export Builder
BETAConfigure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.
These exports write the registry — this is not a managed GPO. ⓘ
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Configure validation of ROCA-vulnerable WHfB keys during authentication
; State: Enabled
; Supported on: At least Windows Vista
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM]
"SamNGCKeyROCAValidation"=dword:00000002More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Configure validation of ROCA-vulnerable WHfB keys during authentication
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'SamNGCKeyROCAValidation' -Value 2 -Type DWordIntune XML
OMA-URI: ./Device/Vendor/MSFT/Policy/Config/ADMX_sam/SamNGCKeyROCAValidation
Data type: String
Value:
<enabled/>
<data id="SamNGCKeyROCAValidation_Settings" value="2"/>Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Configure validation of ROCA-vulnerable WHfB keys during authentication
# State: Enabled
# Supported on: At least Windows Vista
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM' -Name 'SamNGCKeyROCAValidation' -Expected 2 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Configure validation of ROCA-vulnerable WHfB keys during authentication
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'SamNGCKeyROCAValidation' -Value 2 -Type DWordSCCM scripts
# Exported from gporais.com
# Policy: Configure validation of ROCA-vulnerable WHfB keys during authentication
# State: Enabled
# Supported on: At least Windows Vista
# SCCM Configuration Item guidance:
# Create a Configuration Item of type "Setting: Script".
# Discovery script: use the Detection script below.
# Remediation script: use the Remediation script below.
# Compliance rule: the Discovery script output equals 'Compliant'.
# === Detection script ===
# Exported from gporais.com
# Policy: Configure validation of ROCA-vulnerable WHfB keys during authentication
# State: Enabled
# Supported on: At least Windows Vista
function Test-RegistryValue {
param(
[Parameter(Mandatory = $true)][string]$Path,
[Parameter(Mandatory = $true)][string]$Name,
[object]$Expected,
[ValidateSet('String', 'DWord', 'MultiString')][string]$Kind = 'String',
[switch]$Absent
)
try {
$item = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction Stop
} catch {
return $Absent.IsPresent
}
if ($Absent.IsPresent) { return $false }
$actual = $item.$Name
if ($Kind -eq 'DWord') { return ([int64]$actual) -eq ([int64]$Expected) }
if ($Kind -eq 'MultiString') {
$actualValues = @($actual)
$expectedValues = @($Expected)
if ($actualValues.Count -ne $expectedValues.Count) { return $false }
for ($i = 0; $i -lt $expectedValues.Count; $i++) {
if ([string]$actualValues[$i] -ne [string]$expectedValues[$i]) { return $false }
}
return $true
}
return [string]$actual -eq [string]$Expected
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM' -Name 'SamNGCKeyROCAValidation' -Expected 2 -Kind DWord)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Configure validation of ROCA-vulnerable WHfB keys during authentication
# State: Enabled
# Supported on: At least Windows Vista
$path = 'HKLM:\Software\Microsoft\Windows\CurrentVersion\Policies\System\SAM'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'SamNGCKeyROCAValidation' -Value 2 -Type DWordBuilding a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.