What is XSS and how does it work?

Cross-Site Scripting (XSS) is a type of web vulnerability that allows an attacker to inject malicious code into a website or web application. This code is then executed by unsuspecting users when they visit the compromised site, allowing the attacker to steal sensitive information, redirect users to malicious sites, or perform other malicious actions.

There are several types of XSS attacks, including:

1. Reflected XSS: This type of attack occurs when an attacker injects malicious code into a website through a user input field (such as a search bar). The code is then reflected back to the user, who is tricked into executing it.
2. Stored XSS: This type of attack involves injecting malicious code into a website's database, where it is stored and executed every time a user accesses the affected page.
3. DOM-based XSS: This type of attack occurs when an attacker manipulates the Document Object Model (DOM) of a website to inject malicious code.

To prevent XSS attacks, it is important to properly validate and sanitize user input and to use content security policies to limit the types of scripts that can be executed on a website. It is also important to keep the website's software and libraries up to date, as many XSS vulnerabilities can be exploited through outdated or unpatched software.

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