AOS, when used as a VPN Gateway, must disable split-tunneling for remote client VPNs.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-267000	SRG-NET-000369-VPN-001620	ARBA-VN-001620	SV-267000r1040766_rule	2024-10-29	1

Description
Split tunneling would in effect allow unauthorized external connections, making the system more vulnerable to attack and to exfiltration of organizational information. A VPN hardware or software client with split tunneling enabled provides an unsecured backdoor to the enclave from the internet. With split tunneling enabled, a remote client has access to the internet while at the same time has established a secured path to the enclave via an IPsec tunnel. A remote client connected to the internet that has been compromised by an attacker on the internet provides an attack base to the enclave's private network via the IPsec tunnel. Hence, it is imperative that the VPN gateway enforces a no split-tunneling policy to all remote clients.

Description

Split tunneling would in effect allow unauthorized external connections, making the system more vulnerable to attack and to exfiltration of organizational information. A VPN hardware or software client with split tunneling enabled provides an unsecured backdoor to the enclave from the internet. With split tunneling enabled, a remote client has access to the internet while at the same time has established a secured path to the enclave via an IPsec tunnel. A remote client connected to the internet that has been compromised by an attacker on the internet provides an attack base to the enclave's private network via the IPsec tunnel. Hence, it is imperative that the VPN gateway enforces a no split-tunneling policy to all remote clients.

ℹ️ Check
Verify the AOS configuration with the following commands: show wlan virtual-ap For each active WLAN virtual-ap profile: show wlan virtual-ap <name> \| include "Forward mode" show ap system-profile For each active AP system-profile: show ap system-profile <name> \| include "Double Encrypt" show aaa authentication via connection-profile For each referenced profile: show aaa authentication via connection-profile <name> \| include "Enable split tunneling" If any instances of remote access or virtual-ap profile forward mode of split-tunnel are found or if double-encrypt is not enabled per active AP system profile, this is a finding.

ℹ️ Check

Verify the AOS configuration with the following commands: show wlan virtual-ap For each active WLAN virtual-ap profile: show wlan virtual-ap <name> | include "Forward mode" show ap system-profile For each active AP system-profile: show ap system-profile <name> | include "Double Encrypt" show aaa authentication via connection-profile For each referenced profile: show aaa authentication via connection-profile <name> | include "Enable split tunneling" If any instances of remote access or virtual-ap profile forward mode of split-tunnel are found or if double-encrypt is not enabled per active AP system profile, this is a finding.

✔️ Fix
Configure AOS using the following commands: configure terminal wlan virtual-ap <profile name> forward-mode tunnel exit write memory ap system-profile <profile name> double-encrypt exit write memory For each VIA connection profile: vaaa authentication via connection-profile <name> no split-tunneling exit write memory