Title

The Server Message Block (SMB) v1 protocol must be disabled on the SMB client. (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

Different methods are available to disable SMBv1 on Windows 10, if V-220729 is configured, this is NA. If the following registry value is not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\mrxsmb10\ Value Name: Start Type: REG_DWORD Value: 0x00000004 (4)

Fix Text

Configure the policy value for Computer Configuration >> Administrative Templates >> MS Security Guide >> "Configure SMBv1 client driver" to "Enabled" with "Disable driver (recommended)" selected for "Configure MrxSmb10 driver". This policy setting requires the installation of the SecGuide custom templates included with the STIG package. "SecGuide.admx" and "SecGuide.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively. The system must be restarted for the changes to take effect.

Additional Identifiers

Rule ID: SV-220731r793191_rule

Vulnerability ID: V-220731

Group Title: SRG-OS-000095-GPOS-00049

Expert Comments

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