Book Image

Web Penetration Testing with Kali Linux - Third Edition

By : Gilberto Najera-Gutierrez, Juned Ahmed Ansari
Book Image

Web Penetration Testing with Kali Linux - Third Edition

By: Gilberto Najera-Gutierrez, Juned Ahmed Ansari

Overview of this book

Web Penetration Testing with Kali Linux - Third Edition shows you how to set up a lab, helps you understand the nature and mechanics of attacking websites, and explains classical attacks in great depth. This edition is heavily updated for the latest Kali Linux changes and the most recent attacks. Kali Linux shines when it comes to client-side attacks and fuzzing in particular. From the start of the book, you'll be given a thorough grounding in the concepts of hacking and penetration testing, and you'll see the tools used in Kali Linux that relate to web application hacking. You'll gain a deep understanding of classicalSQL, command-injection flaws, and the many ways to exploit these flaws. Web penetration testing also needs a general overview of client-side attacks, which is rounded out by a long discussion of scripting and input validation flaws. There is also an important chapter on cryptographic implementation flaws, where we discuss the most recent problems with cryptographic layers in the networking stack. The importance of these attacks cannot be overstated, and defending against them is relevant to most internet users and, of course, penetration testers. At the end of the book, you'll use an automated technique called fuzzing to identify flaws in a web application. Finally, you'll gain an understanding of web application vulnerabilities and the ways they can be exploited using the tools in Kali Linux.
Table of Contents (19 chapters)
Title Page
Copyright and Credits
Packt Upsell

Mitigating AJAX, HTML5, and client-side vulnerabilities

The key to preventing client-side vulnerabilities, or at least to minimizing their impact, is never to trust external information, be it from a client application, web service, or the server inputs. These must always be validated before processing them, and all of the data being shown to users must be properly sanitized and formatted before displaying it in any format (such as HTML, CSV, JSON, and XML). It is a good practice to do a validation layer on the client-side, but that cannot be a replacement for server-side validation.

The same thing happens with authentication and authorization checks. Some effort can be made to reduce the number of invalid requests that reach the server, but the server-side code must verify that the requests that reach it are indeed valid and allowed to proceed to the user's session that is sending such requests.

For AJAX and HTML5, correctly configuring the server and parameters, such as cross origin, content...