Exploit Cross-Site Scripting (XSS) Vulnerability

An XSS attack enables malicious users to inject client-side scripts such as JavaScript codes into web pages viewed by other users. The term XSS is used to describe both the vulnerability and the attack type, such as XSS attack / XSS vulnerability on the web application.

1) Log into Windows 7 Attacker on the Netlab environment.

2) Open Firefox by clicking the icon on the desktop or start menu

3) Visit this page http://192.168.2.15/dvwa/login.php

This is the “Damn Vulnerable Web Application” hosted on the OWASP BWA machine on Netlab.

4) Log in to web application by typing user as Username and user as Password. After logging in, you will see the page below.

5) Click on the XSS reflected on the left menu and type your nickname into the textbook at the right pane of the webpage. (I typed “ethical” and clicked the submit button. The web application gets what you typed as the input, add Hello to the beginning, and prints to the screen.

6)Try some basic HTML tags now. Type <h1>your nickname</h1>

I typed “<h1>ethical</h1> and then clicked submit button. I confirm that it has been formatted as the header. This is an indication that this simple web application is vulnerable to XSS attacks.

7)Try some other tags that are as innocent as header tag. Such as <script>alert(document.cookie)</script>

Take a screen capture showing the session ID.

This small script shows the cookie of your session, a highly sensitive piece of data. This is a proof-of-concept for the XSS attack. An attacker may steal your session cookie leveraging an XSS attack. For XSS attacks, the sky is the limit. You can inject code to the website with the help of forms. Think about this scenario: You inject code to the product review page on an e-commerce site. Internet browsers of everybody who visits that page run a script, and that script sends the cookie of the user to the server of the attacker in an encrypted way.