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

JavaScript

Client-side JavaScript can, of course, be accessed without requiring any privileged access to the application, enabling you to perform a security-focused code review in any situation. A key focus of this review is to identify any vulnerabilities such as DOM-based XSS, which are introduced on the client component and leave users vulnerable to attack (see Chapter 12). A further reason for reviewing JavaScript is to understand what kinds of input validation are implemented on the client, and also how dynamically generated user interfaces are constructed.

When reviewing JavaScript, you should be sure to include both .js files and scripts embedded in HTML content.

The key APIs to focus on are those that read from DOM-based data and that write to or otherwise modify the current document, as shown in Table 19.12.

Table 19.12 JavaScript APIs That Read from DOM-Based Data

API Description
document.location
 document.URL
 document.URLUnencoded
 document.referrer...