Windows Server 2019 setting Microsoft network client: Digitally sign communications (if server agrees) must be configured to Enabled.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-205826SRG-OS-000423-GPOS-00187WN19-SO-000170SV-205826r958908_rule2025-02-253
Description
The server message block (SMB) protocol provides the basis for many network operations. If this policy is enabled, the SMB client will request packet signing when communicating with an SMB server that is enabled or required to perform SMB packet signing. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188
ℹ️ Check
If the following registry value does not exist or is not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\ Value Name: EnableSecuritySignature Value Type: REG_DWORD Value: 0x00000001 (1)
✔️ Fix
Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Microsoft network client: Digitally sign communications (if server agrees)" to "Enabled".