The Server Message Block (SMB) v1 protocol must be disabled on the Windows 2012 SMB server.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-73519	WN12-00-000170	SV-88193r1_rule		Medium

Description
SMBv1 is a legacy protocol that uses the MD5 algorithm as part of SMB. MD5 is known to be vulnerable to a number of attacks such as collision and preimage attacks as well as not being FIPS compliant. Disabling SMBv1 support may prevent access to file or print sharing resources with systems or devices that only support SMBv1. File shares and print services hosted on Windows Server 2003 are an example, however Windows Server 2003 is no longer a supported operating system. Some older network attached devices may only support SMBv1.

Description

SMBv1 is a legacy protocol that uses the MD5 algorithm as part of SMB. MD5 is known to be vulnerable to a number of attacks such as collision and preimage attacks as well as not being FIPS compliant. Disabling SMBv1 support may prevent access to file or print sharing resources with systems or devices that only support SMBv1. File shares and print services hosted on Windows Server 2003 are an example, however Windows Server 2003 is no longer a supported operating system. Some older network attached devices may only support SMBv1.

STIG	Date
Windows Server 2012/2012 R2 Domain Controller Security Technical Implementation Guide	2017-06-09

Details

Check Text ( C-73887r1_chk )
This applies to Windows 2012. Windows 2012 R2 uses a different method to disable SMBv1, see WN12-00-000160. 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\LanmanServer\Parameters\ Value Name: SMB1 Type: REG_DWORD Value: 0x00000000 (0)

Fix Text (F-80255r1_fix)
Configure the following registry value to disable the SMBv1 protocol on the SMB server. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\ Value Name: SMB1 Type: REG_DWORD Value: 0x00000000 (0) The system must be restarted for the change to take effect.