Introduction

This tutorial aims to give a comprehensive view of Cross-Site Request Forgery (CSRF), a common web security vulnerability. By the end of this tutorial, you will have a good understanding of what CSRF is, how it works, and how it can be prevented.

What you will learn

1. What is CSRF?
2. How does CSRF work?
3. Potential damages caused by CSRF.
4. Methods to prevent CSRF.

Prerequisites

Basic knowledge of web development and HTTP protocols would be beneficial. Familiarity with HTML, JavaScript, and server-side languages is recommended.

Step-by-Step Guide

Understanding CSRF

CSRF, or Cross-Site Request Forgery, is an attack that tricks the victim into submitting a malicious request. It uses the identity and privileges of the victim to perform an undesired function on their behalf.

How does CSRF work?

CSRF attacks specifically target state-changing requests, not theft of data, since the attacker has no way to see the response to the forged request. With a little help of social engineering, an attacker may trick the users of a web application into executing actions of the attacker's choosing.

Code Examples

Let's consider an example where a banking site utilizes a GET request to transfer money from one account to another:

<a href="http://bank.com/transfer?amt=10000&toAcct=12345">Click here to win a prize!</a>

If a logged-in user clicks on this innocuous-looking link, a transfer will be made (without their knowledge) to account number 12345. This is a simple example of how CSRF attack can be executed.

Summary

In this tutorial, we have learned about CSRF - what it is, how it works, and the damage it can potentially cause. We also briefly touched upon some prevention methods.

Next Steps for Learning

To further solidify your knowledge on CSRF, consider learning more about:
1. CSRF tokens
2. Same-Site Cookies
3. Double Submit Cookies
4. Referer and Origin headers

Practice Exercises

Now that we have a basic understanding of CSRF, let's practice with some exercises:

1. Exercise 1: Create a simple HTML form that could potentially be vulnerable to a CSRF attack.
2. Exercise 2: Given a vulnerable HTML form, suggest some ways to make it secure against CSRF attacks.
3. Exercise 3: Create a simple CSRF token system to protect a form.

Tips for Further Practice

Consider creating a simple web application, and try various methods to secure it against CSRF attacks. Always remember to validate, sanitize, and escape user inputs and outputs.

Remember, practice is key when it comes to learning about web security. The more vulnerabilities you learn to protect against, the stronger your applications will be.