This excerpt is from Chapter 10 Wireless LANs in Hacking for Dummies written by Kevin Beaver and published by Wiley Publishing. You can download the entire chapter here for free.
Wireless local area networks (WLANs) -- specifically, the ones based on the IEEE 802.11 standard -- are increasingly being deployed into both business and home networks. Next to instant messaging and personal video recorders, WLANs are the neatest technology I've used in quite a while. Of course, with any new technology come security issues, and WLANs are no exception. In fact, the 802.11b wireless technology has been the poster child for weak security and network hack attacks for several years running.
WLANs offer a ton of business value, from convenience to reduced network deployment time. Whether your organization allows wireless network access or not, testing for WLAN security vulnerabilities is critical. In this chapter, I cover some common wireless network security vulnerabilities that you should test for. And I discuss some cheap and easy countermeasures you can implement to help ensure that WLANs are not more of a risk to your organization than they're worth.
Understanding the Implications of Wireless Network Vulnerabilities
WLANs are very susceptible to hacker attacks -- even more so than wired networks are. They have vulnerabilities that can allow a hacker to bring your network to its knees and allow your information to be gleaned right out of thin air. If a hacker comprises your WLAN, you can experience the following problems:
- Loss of network access, including e-mail, Web, and other services that can cause business downtime
- Loss of confidential information, including passwords, customer data, intellectual property, and more
- Legal liabilities associated with unauthorized users
Most of the wireless vulnerabilities are in the 802.11 protocol and within wireless access points (APs) -- the central hublike devices that allow wireless clients to connect to the network. Wireless clients have some vulnerabilities as well.
Various fixes have come along in recent years to address these vulnerabilities, but most of these fixes have not been applied or are not enabled by default. You may also have employees installing rogue WLAN equipment on your network without your knowledge; this is the most serious threat to your wireless security and a difficult one to fight off. Even when WLANs are hardened and all the latest patches have been applied, you still may have some serious security problems, such as DoS and man-in-the-middle attacks (like you have on wired networks), that will likely be around for a while.