What constitutes an XSS attack?

An XSS (Cross-Site Scripting) attack occurs when an attacker injects malicious scripts into content that is then delivered to users through a web application. The purpose of these injected scripts is to manipulate client-side scripts executed in the browser of the end user.

A hyperlink that carries malicious content is a classic vector for executing such an attack. When users click on this hyperlink, it may lead them to a site or action that executes the harmful script, potentially compromising session tokens, cookies, or user data. This highlights the significance of ensuring that user input is properly sanitized and that outputs are encoded to protect against such vulnerabilities.

In contrast, server-side scripts, secure login forms, and data encryption methods all focus on securing data and interactions but do not directly relate to the mechanisms through which an XSS attack is carried out.