XSS Exploitation
Explore how to detect and exploit cross-site scripting vulnerabilities in web applications. Understand reflected, DOM, and stored XSS attacks through practical examples and learn how these exploits compromise security. Gain hands-on experience using JavaScript injection methods to identify security flaws and improve web app defenses.
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Overview
Considering the different types of XSS attacks we’ve discussed, it’s fair to assume that the overall process of finding such vulnerabilities is not all that difficult. Despite modern browsers and frameworks having simplified web application development, sometimes a developer has to actually make an effort to add security bugs to their application. Nevertheless, it’s still quite important to know how these vulnerabilities are exploited before delegating the task to an automated tool or service.
Exploiting XSS vulnerabilities
Websites are rendered on the browser (alongside site business logic) as a combination of HTML, CSS, and JavaScript. This means that as long as the browser trusts the sources of the code, JavaScript especially, it will have no problem in executing it.
JavaScript is largely just like any other programming language, although with a few eccentricities. The same goes for HTML. As such, we can use the <script></script> tags to probe for basic vulnerabilities. For example, if a website has a form or a search bar, we can type <script> alert("Hello, World")</script> ...