Network access: Shares that can be accessed anonymously
Verified with Windows Security Options 25H2 — updated on July 13, 2026
Security policy
This is a Security Options policy (Windows Settings > Security Settings), applied by the security engine — not an Administrative Template (ADMX). In GPMC/gpedit it is configured under Local Policies > Security Options.
Path in the GPO console
Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options\Network access Description
This setting lists SMB shares that anonymous users may access. The default list is empty. Adding a share permits unauthenticated access subject to its other permissions and can disclose data if share and file-system access controls are not carefully constrained.
Registry
HKLM
System\CurrentControlSet\Services\LanManServer\Parameters Value name: NullSessionShares
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. ⓘ
Security policy setting: a domain GPO (Security Settings) can overwrite this registry value at the next policy refresh. Prefer configuring it via GPMC > Security Options.
.reg file
Windows Registry Editor Version 5.00
; Exported from gporais.com
; Policy: Network access: Shares that can be accessed anonymously
; State: Enabled
[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanManServer\Parameters]
"NullSessionShares"=dword:00000001
"NullSessionShares"=hex(7):00,00
; REG_MULTI_SZ: one string per input line; edit in regedit if you need richer formatting.More formats (PowerShell, Intune, SCCM)
PowerShell
# Exported from gporais.com
# Policy: Network access: Shares that can be accessed anonymously
# State: Enabled
$path = 'HKLM:\System\CurrentControlSet\Services\LanManServer\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'NullSessionShares' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'NullSessionShares' -Value @() -Type MultiString
# REG_MULTI_SZ: one string per input line; edit in regedit if you need richer formatting.Intune XML
No direct Policy CSP / OMA-URI mapping for this policy. Use the Intune Remediation tab, or ingest the ADMX in Intune.Intune Remediation
# === Detection script ===
# Exported from gporais.com
# Policy: Network access: Shares that can be accessed anonymously
# State: Enabled
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\System\CurrentControlSet\Services\LanManServer\Parameters' -Name 'NullSessionShares' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\System\CurrentControlSet\Services\LanManServer\Parameters' -Name 'NullSessionShares' -Expected @() -Kind MultiString)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Network access: Shares that can be accessed anonymously
# State: Enabled
$path = 'HKLM:\System\CurrentControlSet\Services\LanManServer\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'NullSessionShares' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'NullSessionShares' -Value @() -Type MultiString
# REG_MULTI_SZ: one string per input line; edit in regedit if you need richer formatting.SCCM scripts
# Exported from gporais.com
# Policy: Network access: Shares that can be accessed anonymously
# State: Enabled
# 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: Network access: Shares that can be accessed anonymously
# State: Enabled
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
}
$checks = @(
(Test-RegistryValue -Path 'HKLM:\System\CurrentControlSet\Services\LanManServer\Parameters' -Name 'NullSessionShares' -Expected 1 -Kind DWord)
(Test-RegistryValue -Path 'HKLM:\System\CurrentControlSet\Services\LanManServer\Parameters' -Name 'NullSessionShares' -Expected @() -Kind MultiString)
)
if ($checks -notcontains $false) {
Write-Output 'Compliant'
exit 0
}
Write-Output 'Non-compliant'
exit 1
# === Remediation script ===
# Exported from gporais.com
# Policy: Network access: Shares that can be accessed anonymously
# State: Enabled
$path = 'HKLM:\System\CurrentControlSet\Services\LanManServer\Parameters'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'NullSessionShares' -Value 1 -Type DWord
Set-ItemProperty -Path $path -Name 'NullSessionShares' -Value @() -Type MultiString
# REG_MULTI_SZ: one string per input line; edit in regedit if you need richer formatting.