Web Application Obfuscation: '-/WAFs..Evasion..Filters//alert(/Obfuscation/)-' [Paperback]

Mario Heiderich (Author), Eduardo Alberto Vela Nava (Author), Gareth Heyes (Author), David Lindsay (Author)

Book Description

Publication Date: December 10, 2010 | ISBN-10: 1597496049 | ISBN-13: 978-1597496049 | Edition: 1

Web applications are used every day by millions of users, which is why they are one of the most popular vectors for attackers. Obfuscation of code has allowed hackers to take one attack and create hundreds-if not millions-of variants that can evade your security measures. Web Application Obfuscation takes a look at common Web infrastructure and security controls from an attacker's perspective, allowing the reader to understand the shortcomings of their security systems. Find out how an attacker would bypass different types of security controls, how these very security controls introduce new types of vulnerabilities, and how to avoid common pitfalls in order to strengthen your defenses.

• Looks at security tools like IDS/IPS that are often the only defense in protecting sensitive data and assets
• Evaluates Web application vulnerabilties from the attacker's perspective and explains how these very systems introduce new types of vulnerabilities
• Teaches how to secure your data, including info on browser quirks, new attacks and syntax tricks to add to your defenses against XSS, SQL injection, and more

Editorial Reviews

Review

"As the data stored in Web application systems becomes critical to business, the attacks against them are becoming increasingly complex. If you want to move your understanding beyond 'or 1=1--' this book provides the knowledge needed to bypass both filters and detection, crucial for both attack and defence." -- Andrew Waite, Security Researcher, InfoSanity Research

"Intended for advanced network security administrators, penetration testers and web application developers, this guide to web obfuscation presents an in depth technical discussion of the latest methods in site intrusion and Internet attacks. Chapters examine state of the art obfuscation attacks on major website components such as HTML, JavaScript and VBScript, CSS, PHP, SQL and web application firewalls. A final chapter discusses future problems such as the new HTML 5 standards and plug-in vulnerabilities. Chapters include numerous code examples in a variety of languages and formats. Heiderich is a web developer, Nava is a security researcher for Google, Heyes is a security contractor and Lindsay is a security consultant."--SciTechBookNews

"This is a very frightening book and I would advise any security architect to purchase a copy. It's aimed at the bleeding edge of the technical security market, however, it really does hammer home how difficult security can become when faced with complex applications and protocols. The techniques used in the book are not trivial, but they do show us that the age of the firewall and the IDS may well be over, and the age of security by design has only just begun."--InfoSecReviews.com

"This is a deep technical read and anyone buying it should have a solid understanding of web technologies and some experience of web programming. I would say it is targeted at penetration testers and security architects, but to the security generalist it also opens up new frontiers when it comes to designing for security."--Best Hacking and Pen Testing Books in InfoSecReviews Book Awards

From the Back Cover

Web applications are used every day by millions of users, which is why they are one of the most popular vectors for attackers. Obfuscation of code has allowed hackers to take one attack and create hundreds-if not millions-of variants that can evade your security measures. Web Application Obfuscation takes a look at common Web infrastructure and security controls from an attacker's perspective, allowing the reader to understand the shortcomings of their security systems. Find out how an attacker would bypass different types of security controls, how these very security controls introduce new types of vulnerabilities, and how to avoid common pitfalls in order to strengthen your defenses.

See all Editorial Reviews

Product Details

• Paperback: 282 pages
• Publisher: Syngress; 1 edition (December 10, 2010)
• Language: English
• ISBN-10: 1597496049
• ISBN-13: 978-1597496049
• Product Dimensions: 7.5 x 0.9 x 9.2 inches
• Shipping Weight: 1.4 pounds (View shipping rates and policies)
• Average Customer Review: 3.8 out of 5 stars  See all reviews (10 customer reviews)
• Amazon Best Sellers Rank: #303,455 in Books (See Top 100 in Books)
  • #69 in Books > Computers & Technology > Programming > Algorithms > Cryptography

Most Helpful Customer Reviews

6 of 6 people found the following review helpful

4.0 out of 5 stars I bought this book on faith and it delivered March 31, 2011

By Richard Bejtlich

Format:Paperback

I had really no idea what to expect when I started reading Web Application Obfuscation (WAO). I hoped it would address attacks on Web technologies, perhaps including evasion methods, but beyond that I didn't even really know how to think about whatever problem this book might address. After finishing WAO, it's only appropriate to say "wow." In short, I had no idea that Web browsers (often called "user agents" in WAO) are so universally broken. Web browser developers would probably reply that they're just trying to handle as much broken HTML as possible, but the WAO authors show this approach makes Web "security" basically impossible. I recommend reading WAO to learn just how crazy one can be when interacting with Web apps.

Speaking of crazy: ch 4 was off the hook. For example, p 121 speaks of the "great Javascript Charwall" by saying: "6 is the fewest number of characters possible which allow arbitrary Javascript to be executed." What!? I had no idea anyone spent time on these sorts of issues, and worse, that intruders could use these techniques to evade a slew of security mechanisms. This was a primary strength of WAO: bringing the reader into a world where obfuscation is an obsession.

I liked many other aspects of WAO. The book was very thorough. For one example, check the table on p 27. For another, see the regex explanation with examples in ch 1. The book has many such sections where the authors offer great detail on the subject at hand. I also enjoyed the many references to outside work. Authors of all technical books should follow WAO's lead, because 1) it gives credit where due and 2) it shows the authors are aware of outside influences and up-to-date.

WAO also does a nice job explaining how we arrived at the current state of broken Web technologies. Their history lesson of the browser wars in ch 2 set the stage for the chaos that follows. I'll finish my praises by mentioning the Web site the authors created as a companion to the book, complete with errata and code listings; it's a nice addition to the book.

If you're wondering why I rated WAO four instead of five stars, the reason involves the audience. I think too often the authors advance pretty far beyond the uninitiated reader. You have to admit that if obfuscation is your world, you're probably not going to read this book. However, if you're a newbie like me, you need the authors to spend more time explaining what they're doing and more importantly, WHY. Just what is the purpose of this technique or that attack? I think if the authors recruited some outside help to walk through the book, slow them down, and answer some basic questions, a second edition would be an easy five star work.

On the production side, a new edition should redraw figures 5.2 - 5.14. They look like they came straight from a PowerPoint pitch.

Overall, WAO is a great book to shatter any assumptions you may have about how Web clients and servers render content. Maybe the authors would care to describe how best one can operate in such a dangerous environment, i.e., is their an OpenBSD for Web technologies? All of the engines seem bad -- what's a user to do?

2 of 2 people found the following review helpful

5.0 out of 5 stars take client-side attacks to the next level March 12, 2011

By Ari Elias Bachrach

Format:Paperback|Amazon Vine™ Review (What's this?)

As so many attacks have begun to move to targeting the client, it's helpful to understand how the client (which is usually a browser), handles what it's given. This book goes through several technologies including HTML, Javascript, VB script, CSS, PHP, and SQL, and shows how the normal syntax can be obfuscated. For the most part the authors present most of the material as background information, and don't bother connecting the dots to show you how their techniques could be used in an attack. The assumption is that the reader is already very familiar with web application security, and can apply the knowledge provided.

I learned something in every chapter. Some of the more interesting things addressed were:
* Non-alphanumeric Javascript. In other words, functional Javascript that consist of no letters or numbers.
* There was a very detailed discussion of alternate ways to execute Javascript within the DOM. Many of these techniques could be used to bypass filters.
* How using non-standard character sets can confuse browsers and possibly bypass filters.
* How different browsers handle non-standard compliant markup, some of which could lead to script execution.
* How to launch a port scan using CSS.
* Executing code within CSS.

PHP, being server-side code, seems to be the odd man out in this book, but I guess they included it only for the sake of completeness. The title would have led me to believe there was a greater discussion of WAFs, but in fact it only got a few pages and the cursory conclusion of "they can probably be bypassed". While that was disappointing it still doesn't detract from the great reference material presented here.

1 of 1 people found the following review helpful

5.0 out of 5 stars Comprehensive, Technical and Packed with Useful Information September 30, 2011

By Stuart Gardner VINE™ VOICE

Format:Paperback|Amazon Vine™ Review (What's this?)

This book really makes the case for obfuscation techniques. Many security books try to cover a broad field of topics - this doesn't. It is highly focussed, very technical and well written. Not an introductory book, a good working knowledge of site design, Javascript and PHP is really a must.