1.
What is a Cross-Site Scripting (XSS) vulnerability? Explain it specifically in the context of innerHTML being used with unsanitized user input.
2.
Provide a simple, concrete example of a malicious script that could be injected by a user in this scenario. Show how this script would exploit the vulnerability and what its effect would be (e.g., stealing cookies, redirecting).
3.
How would you fix this vulnerability? Detail the primary methods. First, explain HTML Sanitization, what it means, and provide an example of a sanitization library or method.
4.
Explain why using textContent is a safer alternative than innerHTML when only plain text is intended.
5.
Mention other best practices for preventing XSS vulnerabilities, such as Content Security Policy (CSP).