The Windows Server 2025 setting Microsoft network client: Digitally sign communications (if server agrees) must be configured to Enabled.

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

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)

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".