Forescout must be configured to apply dynamic ACLs that restrict the use of ports when non-entity endpoints are connected using MAC Authentication Bypass (MAB). This is required for compliance with C2C Step 4.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-233327	FORE-NC-000190	SV-233327r811403_rule		Medium

Description

MAB is only one way of connecting non-entity endpoints, and can be defeated by spoofing the MAC address of an assumed authorized device. By adding the device to the MAR, the device can then gain access to the network. NPE devices that can support PKI or an allowed authentication type must use PKI. MAB may be used for NPE that cannot support an approved device authentication. Non-entity endpoints include Internet of Things (IoT) devices, VoIP phone, and printer.

STIG	Date
Forescout Network Access Control Security Technical Implementation Guide	2021-12-17

Details

Check Text ( C-36522r811402_chk )
If DoD is not at C2C Step 4 or higher, this is not a finding. Verify Forescout applies dynamic ACLs that restrict the use of ports when non-entity endpoints are connected using MAC Address Repository (MAR). If the NAC does not apply dynamic ACLs that restrict the use of ports when non-entity endpoints are connected using MAR, this is a finding.

Fix Text (F-36487r803471_fix)

Use the Forescout Administrator UI to configure the policy which identifies non-entity endpoints to complete a control action when a device is added to the MAR. 1. Log on to Forescout UI. 2. In the Policy tab, locate the Authentication and Authorization policy set. 3. Select a policy that identifies non-entity endpoints. Highlight the policy, then select "Edit". 4. From the Sub-Rules section, ensure that when a device is added to the MAR, the policy also applies one of the following actions: -Access Port ACL -Endpoint Address ACL -WLAN Role