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

Transmitting Data Via the Client

It is common to see an application passing data to the client in a form that the end user cannot directly see or modify, with the expectation that this data will be sent back to the server in a subsequent request. Often, the application's developers simply assume that the transmission mechanism used will ensure that the data transmitted via the client will not be modified along the way.

Because everything submitted from the client to the server is within the user's control, the assumption that data transmitted via the client will not be modified is usually false and often leaves the application vulnerable to one or more attacks.

You may reasonably wonder why, if the server knows and specifies a particular item of data, the application would ever need to transmit this value to the client and then read it back. In fact, writing applications in this way is often easier for developers for various reasons:

  • It removes the need to keep track of all...