Chapter 1, Wireless Lab Setup, introduces dozens of exercises that we will be doing in this book. In order to be able to try them out, the reader will need to set up a wireless lab. This chapter focuses on how to create a wireless testing lab using off the shelf hardware and open source software. We will first look at the hardware requirements which include wireless cards, antennas, access points, and other Wi-Fi-enabled devices, then we will shift our focus to the software requirements which include the operating system, Wi-Fi drivers, and security tools. Finally, we will create a test bed for our experiments and verify different wireless configurations on it.

Chapter 2, WLAN and its Inherent Insecurities, focuses on the inherent design flaws in wireless networks which makes them insecure out-of-the-box. We will begin with a quick recap of the 802.11 WLAN protocols using a network analyzer called Wireshark. This will give us a practical understanding about how these protocols work. Most importantly, we will see how client and access point communication works at the packer level by analyzing Management, Control and Data frames. We will then learn about packet injection and packer sniffing in wireless networks, and look at some tools which enable us to do the same.

Chapter 3, Bypassing WLAN Authentication, talks about how to break a WLAN authentication mechanism! We will go step-by-step and explore how to subvert Open and Shared Key authentications. In course of this, you will learn how to analyze wireless packets and figure out the authentication mechanism of the network. We will also look at how to break into networks with Hidden SSID and MAC Filtering enabled. These are two common mechanisms employed by network administrators to make wireless networks more stealthy and difficult to penetrate, however, these are extremely simple to bypass.

Chapter 4, WLAN Encryption Flaws, discusses one of the most vulnerable parts of the WLAN protocol are the Encryption schemas—WEP, WPA, and WPA2. Over the past decade, hackers have found multiple flaws in these schemas and have written publically available software to break them and decrypt the data. Even though WPA/WPA2 is secure by design, misconfiguring those opens up security vulnerabilities, which can be easily exploited. In this chapter, we will understand the insecurities in each of these encryption schemas and do practical demos on how to break them.

Chapter 5, Attacks on the WLAN Infrastructure, shifts our focus to WLAN infrastructure vulnerabilities. We will look at the vulnerabilities created due to both configuration and design problems. We will do practical demos of attacks such as access point MAC spoofing, bit flipping and replay attacks, rogue access points, fuzzing, and denial of service. This chapter will give the reader a solid understanding of how to do a penetration test of the WLAN infrastructure.

Chapter 6, Attacking the Client, opens your eyes if you have always believed that wireless client security was something you did not have to worry about! Most people exclude the client from their list when they think about WLAN security. This chapter will prove beyond doubt why the client is just as important as the access point when penetrating testing a WLAN network. We will look at how to compromise the security using client side attacks such as mis-association, Caffe Latte, disassociation, ad-hoc connections, fuzzing, honeypots, and a host of others.

Chapter 7, Advanced WLAN Attacks, looks at more advanced attacks as we have already covered most of the basic attacks on both the infrastructure and the client. These attacks typically involve using multiple basic attacks in conjunction to break security in more challenging scenarios. Some of the attacks which we will learn include wireless device fingerprinting, man-in-the-middle over wireless, evading wireless intrusion detection and prevention systems, rogue access point operating using custom protocol, and a couple of others. This chapter presents the absolute bleeding edge in wireless attacks out in the real world.

Chapter 8, Attacking WPA Enterprise and RADIUS, graduates the user to the next level by introducing him to advanced attacks on WPA-Enterprise and the RADIUS server setup. These attacks will come in handy when the reader has to perform a penetration test on a large Enterprise networks which rely on WPA-Enterprise and RADIUS authentication to provide them with security. This is probably as advanced as Wi-Fi attacks can get in the real world.

Chapter 9, Wireless Penetrating Testing Methodology, is where all the learning from the previous chapters comes together, and we will look at how to do a wireless penetration test in a systematic and methodical way. We will learn about the various phases of penetration testing—planning, discovery, attack and reporting, and apply it to wireless penetration testing. We will also understand how to propose recommendations and best practices after a wireless penetration test.

Appendix A, Conclusion and Road Ahead, concludes the book and leaves the user with some pointers for further reading and research.

To follow and recreate the practical exercises in this book, you will need two laptops with built-in Wi-Fi cards, an Alfa AWUS036H USB wireless Wi-Fi adapter, BackTrack 5, and some other hardware and software. We have detailed this in Chapter 1, Wireless Lab Setup.

As an alternative to the two laptop setup, you could also create a Virtual Machine housing BackTrack 5 and connect the card to it over the USB interface. This will help you get started with using this book much faster, but we would recommend a dedicated machine running BackTrack 5 for actual assessments in the field.

As a prerequisite, readers should be aware of the basics of wireless networks. This includes having prior knowledge about the basics of the 802.11 protocol and client access point communication. Though we will briefly touch upon some of this when we set up the lab, it is expected that the user is already aware of these concepts.

Though this book is a Beginner's series, it is meant for all levels of users, from amateurs right through to wireless security experts. There is something for everyone. The book starts with simple attacks but then moves on to explain the more complicated ones, and finally discusses bleeding edge attacks and research. As all attacks are explained using practical demonstrations, it is very easy for readers at all levels to quickly try the attack out by themselves. Please note that even though the book highlights the different attacks which can be launched against a wireless network, the real purpose is to educate the user to become a wireless penetration tester. An adept penetration tester would understand all the attacks out there and would be able to demonstrate them with ease, if requested by his client.

In this book, you will find several headings appearing frequently.

To give clear instructions of how to complete a procedure or task, we use:

Instructions often need some extra explanation so that they make sense, so they are followed with:

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