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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-6832	WN08-SO-000028	SV-48132r1_rule	ECSC-1	Medium

Description
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.

STIG	Date
Windows 8 / 8.1 Security Technical Implementation Guide	2015-11-30

Details

Check Text ( C-44858r1_chk )
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 (always)" 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: RequireSecuritySignature Value Type: REG_DWORD Value: 1

Check Text ( C-44858r1_chk )

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 (always)" 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: RequireSecuritySignature

Value Type: REG_DWORD
Value: 1

Fix Text (F-41269r1_fix)
Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Local Policies -> Security Options -> "Microsoft Network Client: Digitally sign communications (always)" to "Enabled".