Final answer:
Cross-Site Scripting (XSS) is the attack based on a website accepting user input without sanitizing.
Step-by-step explanation:
The attack based on a website accepting user input without sanitizing it is called Cross-Site Scripting (XSS).
XSS is a type of security vulnerability that occurs when a website allows users to input untrusted data, such as in a form field, and then includes that data in its output without properly sanitizing it. This can allow an attacker to inject malicious scripts into web pages that are viewed by other users.
To prevent XSS attacks, websites should implement input validation and sanitization techniques, such as encoding user input or using a web application firewall.