Certified Incident Handler (CIH) Practice Ecam

Which practice is essential for mitigating XSS attacks on a web server?

1. Use testing tools extensively during the design phase

2. Disable Content Security Policy

3. Allow inline JavaScript in application code

4. Ignore cross-origin resource sharing policies

The correct answer is: Use testing tools extensively during the design phase

Using testing tools extensively during the design phase is essential for mitigating Cross-Site Scripting (XSS) attacks on a web server because it allows developers to identify and address potential vulnerabilities before the application is deployed. During the design and development stages, employing testing tools can help simulate attacks, analyze the application's response, and uncover areas where user input could be improperly handled or reflected back to users, potentially leading to XSS vulnerabilities. By identifying issues early, developers can implement appropriate security measures such as input validation, output encoding, and proper handling of user-generated content. In contrast, disabling Content Security Policy is counterproductive, as this policy is designed to help prevent XSS by controlling which resources can be loaded and executed. Allowing inline JavaScript in application code introduces significant risk, as it can be exploited by attackers to inject harmful scripts. Lastly, ignoring cross-origin resource sharing policies can expose applications to various attacks, including XSS, by allowing untrusted domains to interact with your resources. Thus, these practices do not help in mitigating XSS risks and, in fact, may increase the vulnerability of web applications.