2.3.8.3 Ensure 'Microsoft network client: Send unencrypted password to third-party SMB servers' is set to 'Disabled'

Information

This policy setting determines whether the SMB redirector will send plaintext passwords during authentication to third-party SMB servers that do not support password encryption.

It is recommended that you disable this policy setting unless there is a strong business case to enable it. If this policy setting is enabled, unencrypted passwords will be allowed across the network.

The recommended state for this setting is: Disabled.

Rationale:

If you enable this policy setting, the server can transmit passwords in plaintext across the network to other computers that offer SMB services, which is a significant security risk. These other computers may not use any of the SMB security mechanisms that are included with Windows Server 2003.

Impact:

None - this is the default behavior.

Some very old applications and operating systems such as MS-DOS, Windows for Workgroups 3.11, and Windows 95a may not be able to communicate with the servers in your organization by means of the SMB protocol.

Solution

To establish the recommended configuration, set the following Device Configuration Policy to Disabled

To access the Device Configuration Policy from the Intune Home page:

Click Devices

Click Configuration profiles

Click Create profile

Select the platform (Windows 10 and later)

Select the profile (Endpoint protection)

Click Create

Enter a Name

Click Next

Configure the following Setting

Path: Endpoint protection/Local device security options/Microsoft Network Client
Setting Name: Send unencrypted password to third-party SMB servers
Configuration: Block

Select OK

Continue through the Wizard to complete the creation of the profile (profile assignments, applicability etc.)

Note: More than one configuration setting from each of the Configuration profiles (ex: Administrative Templates, Custom etc.) can be added to each Device Configuration Policy.

Note #2: This setting can also be created via a Custom Configuration Profile using the following OMA-URI:

Name: <Enter name>
Description: <Enter Description>
OMA-URI: ./Device/Vendor/MSFT/Policy/Config/LocalPoliciesSecurityOptions/MicrosoftNetworkClient_SendUnencryptedPasswordToThirdPartySMBServers
Data type: Integer
Value: 0

Default Value:

Disabled. (Plaintext passwords will not be sent during authentication to third-party SMB servers that do not support password encryption.)

See Also

https://workbench.cisecurity.org/files/4291