18.6.8.1 Ensure 'Enable insecure guest logons' is set to 'Disabled'

Information

This policy setting determines if the SMB client will allow insecure guest logons to an SMB server.

The recommended state for this setting is: Disabled.

Rationale:

Insecure guest logons are used by file servers to allow unauthenticated access to shared folders.

Impact:

The SMB client will reject insecure guest logons. This was not originally the default behavior in older versions of Windows, but Microsoft changed the default behavior starting with Windows 10 R1709: Guest access in SMB2 disabled by default in Windows 10 and Windows Server 2016

Solution

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

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/Network access and security
Setting Name: Insecure Guest Logons
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.

Default Value:

Windows 10 R1703 and older: Enabled. (The SMB client will allow insecure guest logons.)

Windows 10 R1709 and newer: Disabled. (The SMB client will reject insecure guest logons.)

See Also

https://workbench.cisecurity.org/benchmarks/14664

Item Details

Category: SYSTEM AND INFORMATION INTEGRITY

References: 800-53|SI-4, CSCv7|9.2

Plugin: Windows

Control ID: e17ab34681e68eddcd376984afd2653a9bb8d59cde51b06dd61bfdc4aa41102d