Final answer:
Cross-site scripting (XSS) is a security vulnerability where an attacker injects malicious scripts into a trusted website, leading to various malicious actions. Defenses against XSS attacks include input validation, output encoding, and using secure coding practices.
Step-by-step explanation:
Cross-site scripting (XSS) is a type of security vulnerability found in web applications. In this attack, an attacker injects malicious scripts into a trusted website, which is then executed by the user's browser.
The attacker can steal sensitive data, such as login credentials or personal information, from unsuspecting users. They can also modify the content of the website, redirect users to malicious sites, or perform other malicious actions.
Some defenses against XSS attacks include input validation and sanitization, output encoding, and using secure coding practices like using prepared statements in database queries. Web application firewalls can also help detect and block XSS attacks.