SV-220925r958908: The Windows SMB client must be configured to always perform SMB packet signing. | Microsoft Windows 10 STIG SCAP Benchmark

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Assessment Title

Rule Text

The Windows SMB client must be configured to always perform SMB packet signing.

Description

Discussion Text

The server message block (SMB) protocol provides the basis for many network operations. Digitally signed SMB packets aid in preventing man-in-the-middle attacks. If this policy is enabled, the SMB client will only communicate with an SMB server that performs SMB packet signing.

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

IA Controls

NIST SP 800-53

Not mappedCCI-002418Not mappedCCI-002421V-63703SV-78193

References

DPMS Target Microsoft Windows 10 DISA DPMS Target Microsoft Windows 10 4072

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.stig.windows10:def:220925
# The Windows SMB client must be configured to always perform SMB packet signing.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Verifies 'Microsoft Network Client: Digitally sign communications (always)' is set to 'Enabled'
# 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\System\CurrentControlSet\Services\LanmanWorkstation\Parameters').GetValueKind('RequireSecuritySignature').ToString()]) -eq 'reg_dword') -and (((Get-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanmanWorkstation\Parameters' -Name 'RequireSecuritySignature' -ErrorAction SilentlyContinue) | Select-Object -ExpandProperty 'RequireSecuritySignature') -eq 1))
}

if (test_1) {
  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 ms_windows_10 target this check assesses.

# OVAL definition: oval:mil.disa.stig.windows10:def:220925
$regPath = "HKLM:\System\CurrentControlSet\Services\LanmanWorkstation\Parameters"
$regKey = "RequireSecuritySignature"
if (Test-Path $regPath -and (Get-ItemProperty -Path $regPath -Name $regKey -ErrorAction SilentlyContinue).RequireSecuritySignature -eq 1) { Write-Output "PASS"; Exit 0 } else { Write-Output "FAIL"; Exit 1 }

Remediation

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Microsoft network client: Digitally sign communications (always)" to "Enabled".