Welcome to the third lesson of our Server-Side Request Forgery (SSRF) Prevention in Express course! We've covered what SSRF is and how to prevent it in Express applications. Now, let's focus on an equally important aspect: monitoring and responding to SSRF incidents. Even with robust prevention measures, it's essential to detect and respond to potential attacks quickly. Let's dive in! 🔍

Monitoring is a critical component of a comprehensive security strategy. It allows you to:

1. Detect potential SSRF attacks in real-time
2. Collect data for forensic analysis
3. Improve your security measures based on attack patterns
4. Respond quickly to minimize damage

Let's explore how to set up effective monitoring for SSRF vulnerabilities in Express applications.

The first step in monitoring is to set up comprehensive request logging. This allows you to track and analyze all incoming requests, making it easier to detect suspicious activity:

In this example, we use the morgan middleware to log all HTTP requests to a file. The 'combined' format includes information such as the IP address, request method, URL, status code, and user agent.

To detect potential SSRF attacks, we need to implement more sophisticated monitoring. Let's create a middleware that specifically looks for suspicious URL patterns:

This middleware checks for suspicious URL patterns that might indicate an SSRF attack attempt. When detected, it logs the incident and triggers an alert.

Alerting is crucial for timely response to potential security incidents. Let's implement a system to alert administrators when suspicious activity is detected:

This code sets up an email alert system using Nodemailer. When a security incident is reported, an email is sent to the administrator with details of the incident.

Having a solid incident response plan is essential for handling security breaches effectively. Let's create a simple incident response handler for SSRF attacks:

This incident handler logs SSRF attempts, alerts the security team, implements mitigation measures, and provides an interface for managing incidents.

In this lesson, we explored the importance of monitoring and responding to SSRF incidents. We learned how to set up request logging, implement advanced SSRF detection, create an alerting system, and develop an incident response plan. By combining these techniques with the prevention measures from the previous lesson, you can create a robust defense against SSRF vulnerabilities in your Express applications.

In the next lesson, we'll dive deeper into security logging and monitoring, exploring more advanced techniques to enhance your application's security posture. Stay tuned! 🚀