Penetration testing is definitely a recommended security discipline that helps you find real vulnerabilities and security wholes before the adversary does. This book is a reference guide of the different penetration testing stages and considerations, covering a wide range of technologies and tools. It is just focused on open-source and freely available tools, and do not include any commercial counterparts, like Core Impact or the specialized Web application testing suites. Perhaps this is a good addition for a future edition without the "open-source" term on its title.
The wide scope of the book is one of the reasons why it is not extremely cutting-edge and does not go into the deep details required to master each topic covered. I completely understand it is not possible to create such a book (at least with less than 9999 pages), covering a wide range of topics and including in-depth details. Overall, this book is a good reference guide (in fact one of the few generic references) that will open the door for more advanced knowledge from other books focused on specific areas, such as wireless, Web applications, databases, etc.
Something that can be quickly appreciated is the involvement of multiple authors, as the quality and look and feel of chapters varies. I specially liked the first two chapters, focused on Recon, Enumeration and Scanning. Even if you're an experience pen-tester, I've been doing penetration tests since 2000, you can easily identify the positive SensePost influence on these chapters, and the section contains valuable tips and tricks. At some extent, the "you always have something new to learn" principle applies here.
The book is really good emphasizing best practices and suggestions from a professional pen-testing perspective. When running tests over production environments, there are lots of considerations to need to have in mind, beyond the pure attack techniques. The book does an excellent work on this area, and this is also ratified by the final chapter detailing how to build your own pen-testing lab, including common political and technical issues (I can confirm I've seen lots of them in real world situations). Once you run pen-tests frequently, you need to customize and build your own scripts and tool set. The book also emphasizes this by explaining how to customize the Backtrack CD with your own additions. Definitely, it is a good approach as Backtrack is the reference pen-testing Linux Live CD distribution nowadays.
At first sight, the book structure is a bit strange and it seems there is a lot of repetition on each and every chapter, but once you get used to it, I think is a great approach. Each chapter introduces the goals and scope, then covers the technologies (or pen-testing phases) analyzed, plus the hacking techniques and vulnerabilities involved, and after that it focuses on the tools required to implement the attacks and how to use them, with practical and detailed examples.
It is crucial to differentiate between the techniques and foundations, and the tools, as multiple tools can be used for the same attack, sometimes you do not even need any hacking tool, and new tools will come in the future. I recommend you to master the techniques, the attack principles, and understand the vulnerabilities, and from there, select the best tool on each case. All this structure is complemented with a final case studies subsection on each chapter that exemplifies real-world situations where the techniques and tools can be applied, and how.
The databases, wireless and network devices hacking chapters are good. They provide some insight in the methodology, hacking tools and techniques available for these type of targets. The database hacking focuses on MS SQL Server and Oracle, for sure the most common DB's available out there. The wireless section mainly focuses on WiFi, and Bluetooth is barely mentioned; not enough. And finally, the network devices chapter is a must, as these systems are typically forgotten, although they manage all the network traffic and are a critical IT component of any organization.
In particular, I didn't like too much the Web application chapter. Although it contains lots of tools references, the structure and methodology presented is not very clear, and there is a kind of mix of tools to perform different tasks. Because Web application pen-testing is one of the cutting-edge areas we are dealing with today, I'd have liked to see more quality and in-depth material on it.
From my point of view, the forensic chapter is not related at all with the book and I would completely remove it. There are other very good forensic books available, so I guess it has been included because the tools and infrastructure for basic forensic analysis is available on Backtrack.
Instead, I would have liked to see more details, practical examples, and resources about vulnerable testing environments, such as the DVL (Damn Vulnerable Linux) distro, WebGoat, the Foundstone hackme suites; just to name a few, as well as Capture-the-Flag scenarios and conference references. It would be great to provide an overview on how to build and break into these testing environments using the tools and techniques covered throughout the book.
I strongly recommend this book to people thinking about, or starting on, the penetration testing field. It provides a good and wide overview of topics you need to master, tools available to launch the appropriate attacks, and other pen-testing best practices. As the book is directly aligned with the Backtrack CD, unfortunately version 2 and not the latest version 3 (time for a new edition, including more Bluetooth stuff and adding VoIP hacking ;)), it has a direct and very strong hands-on component, that allows the reader to test the different tools and examples, and makes it very valuable.