Title

The Windows SMB client must be enabled to perform SMB packet signing when possible. (Cat II impact)

Discussion

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.

Check Content

Analyze the system using the Security Configuration and Analysis snap-in. (See "Performing Analysis with the Security Configuration and Analysis Snap-in" in the STIG Overview document.) Expand the Security Configuration and Analysis tree view. Navigate to Local Policies -> Security Options. If the value for "Microsoft Network Client: Digitally sign communications (if server agrees)" is not set to "Enabled", this is a finding. The policy referenced configures the following registry value: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \System\CurrentControlSet\Services\LanmanWorkstation\Parameters\ Value Name: EnableSecuritySignature Value Type: REG_DWORD Value: 1

Fix Text

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".

Additional Identifiers

Rule ID: SV-48058r1_rule

Vulnerability ID: V-1166

Group Title: SMB Client Packet Signing (if server agrees)

Expert Comments

CCIs tied to check.

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