What security measure can mitigate XSS attacks?

Input validation and output encoding are critical security measures to mitigate XSS (Cross-Site Scripting) attacks. XSS vulnerabilities occur when an attacker injects malicious scripts into web pages viewed by other users. By validating input, you ensure that only expected and safe data is processed by your application. This means checking the data for type, length, format, and range to prevent any unwanted or harmful content from being accepted.

On the other hand, output encoding involves converting characters that have special meaning in HTML, such as "<" and ">", to their corresponding HTML entities (e.g., "<" and ">"). This ensures that any data rendered on a web page does not execute as code, but is treated as plain text instead. Together, these practices provide a robust defense against XSS by ensuring that any malicious scripts cannot be injected into the web applications or executed in users' browsers.

Other measures like regular software updates, using strong passwords, and implementing multi-factor authentication focus on securing user access and maintaining software integrity, but they do not specifically address the issues that lead to XSS vulnerabilities. While those measures are vital for overall cyber security hygiene, they do not directly protect against the injection and execution of malicious scripts within a web application.