How would you address and mitigate potential security vulnerabilities in a web application that utilizes client-side scripting technologies like JavaScript?

To address and mitigate potential security vulnerabilities in a web application that utilizes client-side scripting technologies like JavaScript, there are several best practices that can be followed:

1. Input validation: Ensure that all user inputs are validated on the server side to prevent Cross-Site Scripting (XSS) attacks.

2. Sanitizing user input: Use proper sanitization techniques to prevent injection attacks such as SQL injection and code injection.

3. Content Security Policy (CSP): Implement a CSP to control which resources the browser is allowed to load for the web application, thereby reducing the risk of Cross-Site Scripting attacks.

4. Avoid inline scripting: Avoid inline JavaScript code and use external scripts instead to reduce the risk of XSS vulnerabilities.

5. Secure communication: Utilize HTTPS to encrypt data transmission between the client and the server to prevent Man-in-the-Middle (MitM) attacks.

6. Avoid storing sensitive data: Avoid storing sensitive information such as passwords or API keys in client-side scripts to prevent exposure to potential attackers.

7. Regular security updates: Stay informed about the latest security vulnerabilities and ensure that the web application's libraries and dependencies are regularly updated to patch any known security issues.

By following these best practices and staying vigilant about security vulnerabilities, web developers can help mitigate the risks associated with client-side scripting technologies like JavaScript in web applications.