The Cisco ASA remote access VPN server must be configured to use a separate authentication server than that used for administrative access.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-239965	SRG-NET-000166-VPN-000580	CASA-VN-000390	SV-239965r666301_rule	2024-08-22	2

Description
The VPN interacts directly with public networks and devices and should not contain user authentication information for all users. AAA network security services provide the primary framework through which a network administrator can set up access control and authorization on network points of entry or network access servers. It is not advisable to configure access control on the VPN gateway or remote access server. Separation of services provides added assurance to the network if the access control server is compromised.

Description

The VPN interacts directly with public networks and devices and should not contain user authentication information for all users. AAA network security services provide the primary framework through which a network administrator can set up access control and authorization on network points of entry or network access servers. It is not advisable to configure access control on the VPN gateway or remote access server. Separation of services provides added assurance to the network if the access control server is compromised.

ℹ️ Check
In the example below, radius server at 10.1.1.2 is used for administrative access authentication while the LDAP server will be used for granting remote access to the network. aaa-server LDAP protocol ldap aaa-server LDAP (INSIDE) host 10.1.1.1 … … … aaa-server RADIUS_GROUP protocol radius aaa-server RADIUS_GROUP (INSIDE) host 10.1.1.2 key ***** … … … aaa authentication serial console RADIUS_GROUP LOCAL aaa authentication ssh console RADIUS_GROUP LOCAL If the ASA is not configured to use a separate authentication server than that used for administrative access, this is a finding.

ℹ️ Check

In the example below, radius server at 10.1.1.2 is used for administrative access authentication while the LDAP server will be used for granting remote access to the network. aaa-server LDAP protocol ldap aaa-server LDAP (INSIDE) host 10.1.1.1 … … … aaa-server RADIUS_GROUP protocol radius aaa-server RADIUS_GROUP (INSIDE) host 10.1.1.2 key ***** … … … aaa authentication serial console RADIUS_GROUP LOCAL aaa authentication ssh console RADIUS_GROUP LOCAL If the ASA is not configured to use a separate authentication server than that used for administrative access, this is a finding.

✔️ Fix
Configure the ASA to use a separate authentication server as shown in the example below. ASA2(config)# aaa-server LDAP protocol ldap ASA2(config)# aaa-server LDAP (INSIDE) host 10.1.1.1