Book Image

Kali Linux Web Penetration Testing Cookbook

By : Gilberto Najera-Gutierrez
Book Image

Kali Linux Web Penetration Testing Cookbook

By: Gilberto Najera-Gutierrez

Overview of this book

Web applications are a huge point of attack for malicious hackers and a critical area for security professionals and penetration testers to lock down and secure. Kali Linux is a Linux-based penetration testing platform and operating system that provides a huge array of testing tools, many of which can be used specifically to execute web penetration testing. This book will teach you, in the form step-by-step recipes, how to detect a wide array of vulnerabilities, exploit them to analyze their consequences, and ultimately buffer attackable surfaces so applications are more secure, for you and your users. Starting from the setup of a testing laboratory, this book will give you the skills you need to cover every stage of a penetration test: from gathering information about the system and the application to identifying vulnerabilities through manual testing and the use of vulnerability scanners to both basic and advanced exploitation techniques that may lead to a full system compromise. Finally, we will put this into the context of OWASP and the top 10 web application vulnerabilities you are most likely to encounter, equipping you with the ability to combat them effectively. By the end of the book, you will have the required skills to identify, exploit, and prevent web application vulnerabilities.
Table of Contents (17 chapters)
Kali Linux Web Penetration Testing Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

A3 – Preventing cross-site scripting


Cross-site scripting, as seen previously, happens when the data shown to the user is not correctly encoded and the browser interprets it as a script code and executes it. This also has an input validation factor, as a malicious code is usually inserted through input variables.

In this recipe, we will cover the input validation and output encoding required for developers to prevent XSS vulnerabilities in their applications.

How to do it...

  1. The first sign of an application being vulnerable to XSS is that in the page it reflects the exact input given by the user. So, try not to use user-given information to build output text.

  2. When you need to put user-provided data in the output page, validate such data to prevent the insertion of any type of code. We already saw how to do that in the A1 – Preventing injection attacks recipe.

  3. If, for some reason, the user is allowed to input special characters or code fragments, sanitize or properly encode the text before inserting...