Title

The Cisco ACI layer 2 switch must authenticate all network-connected endpoint devices before establishing any connection. (Cat II impact)

Discussion

Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. For distributed architectures (e.g., service-oriented architectures [SOA]), the decisions regarding the validation of authentication claims may be made by services separate from the services acting on those decisions. In such situations, it is necessary to provide authentication decisions (as opposed to the actual authenticators) to the services that need to act on those decisions. This requirement applies to applications that connect either locally, remotely, or through a network to an endpoint device (including, but not limited to, workstations, printers, servers (outside a datacenter), VoIP Phones, and VTC CODECs). Gateways and SOA applications are examples of where this requirement would apply. Device authentication is a solution enabling an organization to manage devices. It is an additional layer of authentication ensuring only specific pre-authorized devices can access the system.

Check Content

Verify the switch configuration has 802.1x authentication implemented for all access switch ports connecting to LAN outlets (i.e., RJ-45 wall plates) or devices not located in the telecom room, wiring closets, or equipment rooms. MAC Authentication Bypass (MAB) must be configured on those switch ports connected to devices that do not support an 802.1x supplicant. Verify the 802.1X Port Authentication policy is configured correctly: 1. On the menu bar, click Fabric >> External Access Policies >> Policies >> Interface >> 802.1X Port Authentication. 2. Right-click "802.1X Port Authentication" and review each 802.1X Port Authentication Policy. - In the Host Mode field, verify "Single Host" is selected. - In the MAC Auth field, verify "EAP_FALLBACK_MAB" is selected. Verify 802.1X Node Authentication is associated with the 802.1X Port Authentication Policy to a Fabric Access Group: 1. On the menu bar, click Fabric >> External Access Policies >> Policies >> Switch >> 802.1X Node Authentication. 2. Right-click "802.1X Node Authentication" and review each 802.1X Node Authentication Policy. - In the Failed-auth EPG field, verify the tenant, application profile, and EPG to deploy to in the case of failed authentication is configured. - In the Failed-auth VLAN. verify the VLAN to deploy to in the case of failed authentication is selected. Verify the 802.1X Node Authentication Policy is applied to each Leaf Switch Policy Group: 1. Navigate to Fabric >> External Access Policies >> Switches >> Leaf Switches >> Policy Groups. 2. Right-click "Policy Groups" to inspect each Access Switch Policy Group. Verify the 802.1X Node Authentication Policy to a Leaf Interface Profile: 1. Navigate to Fabric >> External Access Policies >> Interfaces >> Leaf Interfaces >> Profiles. 2. Right-click "Profiles" and select Leaf Interface Profile. 3. Expand the Interface Selectors table to review the Access Port Selector(s). If 802.1x authentication or MAB is not configured on all access switch ports connecting to LAN outlets or devices not located in the telecom room, wiring closets, or equipment rooms, this is a finding.

Fix Text

Configure 802.1 x authentications on all host-facing access switch ports. To authenticate those devices that do not support 802.1x, MAB must be configured. When configuring the interface for a leaf switch, the port security policy can be chosen from the list of available port security policies. Create an 802.1X Port Authentication Policy: 1. On the menu bar, click Fabric >> External Access Policies >> Policies >> Interface >> 802.1X Port Authentication. 2. Right-click "802.1X Port Authentication" to open Create 802.1X Port Authentication Policy and fill out the form. - In the Host Mode field, select "Single Host—For allowing only one host per port". - In the MAC Auth field, select "EAP_FALLBACK_MAB". - Click "Submit". Configure 802.1X Node Authentication. Associate the 802.1X Port Authentication Policy to a Fabric Access Group: 1. On the menu bar, click Fabric >> External Access Policies >> Policies >> Switch >> 802.1X Node Authentication. - Right-click "802.1X Node Authentication" to open Create 802.1X Node Authentication Policy. - In the Failed-auth EPG field, select the tenant, application profile, and EPG to deploy to in the case of failed authentication. - In the Failed-auth VLAN, select the VLAN to deploy to in the case of failed authentication. 2. To associate the 802.1X Node Authentication Policy to a Leaf Switch Policy Group, navigate to Fabric >> External Access Policies >> Switches >> Leaf Switches >> Policy Groups. - Right-click "Policy Groups" to open Create Access Switch Policy Group. - In the 802.1X Node Authentication Policy field, select the previously created policy. - Click "Submit". 3. To associate the 802.1X Node Authentication Policy to a Leaf Interface Profile, navigate to Fabric >> External Access Policies >> Interfaces >> Leaf Interfaces >> Profiles. - Right-click "Profiles" to open Create Leaf Interface Profile. - Expand the Interface Selectors table to open the Create Access Port Selector dialog box and fill out the form. - In the Interface Policy Group field, select the previously created policy and click "OK". - Click "Submit".

Additional Identifiers

Rule ID: SV-272032r1114076_rule

Vulnerability ID: V-272032

Group Title: SRG-NET-000343-L2S-000016

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.