Beware: The Walls are Listening…
One of the risks that affects all wireless deployments, large or small, is the fact that wireless signals don't stop at your walls. Setting up an AP is kind of like putting an RJ45 Ethernet jack in your parking lot. Attackers can just walk up, “plug in” (associate), and connect to your network. In fact, you don't even need to be in the parking lot. With the right gear and line-of-sight, you can pick up Wi-Fi signals 20-25 miles away. It's not a trivial task, but with amplifiers and high-gain antennas, it's possible to eavesdrop on wireless networks from very far away.
Long-Range EarsPeter Shipley in San Francisco performed some of the earliest wireless security experiments (http://www.dis.org/filez/openlans.pdf). Pete went to the Berkeley hills with a bunch of wireless gear and pointed his equipment at downtown San Francisco. With his parabolic grid antenna and amplifier, he was able to pick up Wi-Fi signals nearly 25 miles away! |
This element of radio frequency (RF) signal proliferation is scary for security professionals because for many years, we could rely upon the controls we placed on our physical perimeter security to protect network integrity. We put locks on doors, guards in stations, and cameras on walls all to prevent an unauthorized person from entering our facility and gaining access to the network. With wireless networks, we can no longer rely upon those security measures.