Title

The Server Message Block (SMB) v1 protocol must be disabled on the SMB server. (Cat II impact)

Discussion

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.

Check Content

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

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.

Additional Identifiers

Rule ID: SV-88183r1_rule

Vulnerability ID: V-73519

Group Title: WIN00-000170

Expert Comments

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