Book Image

The Web Application Hacker's Handbook

By : Dafydd Stuttard, Marcus Pinto
Book Image

The Web Application Hacker's Handbook

By: Dafydd Stuttard, Marcus Pinto

Overview of this book

Web applications are the front door to most organizations, exposing them to attacks that may disclose personal information, execute fraudulent transactions, or compromise ordinary users. This practical book has been completely updated and revised to discuss the latest step-by-step techniques for attacking and defending the range of ever-evolving web applications. Youíll explore the various new technologies employed in web applications that have appeared since the first edition and review the new attack techniques that have been developed, particularly in relation to the client side. The book starts with the current state of web application security and the trends that indicate how it is likely to evolve soon. Youíll examine the core security problem affecting web applications and the defence mechanisms that applications implement to address this problem, and youíll also explore the key technologies used in todayís web application. Next, youíll carry out tasks for breaking into web applications and for executing a comprehensive attack. As you progress, youíll learn to find vulnerabilities in an application's source code and review the tools that can help when you hack web applications. Youíll also study a detailed methodology for performing a comprehensive and deep attack against a specific target. By the end of this book, youíll be able to discover security flaws in web applications and how to deal with them.
Table of Contents (32 chapters)
Free Chapter
1
Cover
2
Title
3
Copyright
4
About the Authors
5
About the Technical Editor
6
MDSec: The Authors’ Company
7
Credits
8
Acknowledgments
31
Index
32
End User License Agreement

Finding and Exploiting XSS Vulnerabilities

A basic approach to identifying XSS vulnerabilities is to use a standard proof-of-concept attack string such as the following:


"><script>alert(document.cookie)</script>

This string is submitted as every parameter to every page of the application, and responses are monitored for the appearance of this same string. If cases are found where the attack string appears unmodified within the response, the application is almost certainly vulnerable to XSS.

If your intention is simply to identify some instance of XSS within the application as quickly as possible to launch an attack against other application users, this basic approach is probably the most effective, because it can be easily automated and produces minimal false positives. However, if your objective is to perform a comprehensive test of the application to locate as many individual vulnerabilities as possible, the basic approach needs to be supplemented with more sophisticated...