1.2.3 Install perimeter firewalls between all wireless networks and the cardholder data environment, and configure these firewalls to deny or, if traffic is necessary for business purposes, permit only authorized traffic between the wireless environment and the cardholder data environment.
1.2.3.a Examine firewall and router configurations to verify that there are perimeter firewalls installed between all wireless networks and the cardholder data environment.
1.2.3.b Verify that the firewalls deny or, if traffic is necessary for business purposes, permit only authorized traffic between the wireless environment and the cardholder data environment.
The known (or unknown) implementation and exploitation of wireless technology within a network is a common path for malicious individuals to gain access to the network and cardholder data. If a wireless device or network is installed without the entity’s knowledge, a malicious individual could easily and “invisibly” enter the network. If firewalls do not restrict access from wireless networks into the CDE, malicious individuals that gain unauthorized access to the wireless network can easily connect to the CDE and compromise account information.
Firewalls must be installed between all wireless networks and the CDE, regardless of the purpose of the environment to which the wireless network is connected. This may include, but is not limited to, corporate networks, retail stores, guest networks, warehouse environments, etc.