Web Server Vulnerability Scanning with ZAP

Objective

Learn how to use OWASP ZAP (Zed Attack Proxy), a popular open-source security tool, to identify vulnerabilities in web servers and applications, and understand how to analyze and remediate the findings.

Purpose

OWASP ZAP is a powerful tool for web application security testing. It helps identify vulnerabilities such as injection flaws, security misconfigurations, and missing security headers. This lab guides you through scanning a web server using ZAP and interpreting the results.

Tools Required

• OWASP ZAP: Installed on Kali Linux or any supported system.
• A test web application or server (e.g., DVWA, OWASP Juice Shop, or a locally hosted application).

Lab Topology

• Kali Linux: Running OWASP ZAP.
• Target Web Server: A test or vulnerable application to scan.

Walkthrough

Task 1: Setting Up OWASP ZAP

1. Install OWASP ZAP:
   • OWASP ZAP is pre-installed on Kali Linux. To verify, run:

     zaproxy -version
     

   • If not installed, install it using:

     sudo apt update && sudo apt install zaproxy -y
     

2. Launch OWASP ZAP:
   • Start ZAP from the terminal:

     zaproxy
     

   • Alternatively, open it from the applications menu.
3. Set Up Browser Proxy:
   • Configure your browser to route traffic through ZAP.
     • Proxy settings:
       • HTTP Proxy: 127.0.0.1
       • Port: 8080
   • Install the ZAP certificate in your browser for HTTPS interception.

Task 2: Scanning a Web Server

1. Identify the Target:
   • Choose the target URL (e.g., http://<target_ip>).
2. Run a Passive Scan:
   • Enter the target URL in the URL to attack field in ZAP’s main window.
   • Click Attack to start a passive scan.
3. Run an Active Scan:
   • Right-click on the target in the Sites tab and select Attack > Active Scan.
   • Configure the scan scope and click Start Scan.
4. Monitor the Scan:
   • View progress in the Active Scan tab.
   • ZAP will test for vulnerabilities like SQL injection, XSS, and more.

Task 3: Interpreting Results

1. View Alerts:
   • Navigate to the Alerts tab to see identified vulnerabilities.
   • Alerts are categorized by severity (e.g., High, Medium, Low).
2. Analyze Findings:
   • Example output:
     • High: SQL Injection detected in /login.php.
     • Medium: Missing X-Frame-Options header.
     • Low: Server discloses version information in HTTP headers.
3. Expand Alert Details:
   • Click on an alert to view detailed information, including:
     • Description of the issue.
     • Steps to reproduce.
     • Recommended remediation actions.

Task 4: Remediating Vulnerabilities

1. Fix High-Severity Issues First:
   • Example: If SQL Injection is detected:
     • Use parameterized queries to sanitize user input.
     • Validate and escape all user inputs.
2. Add Missing Security Headers:
   • Configure the web server to include headers like:
     • X-Frame-Options: DENY
     • Content-Security-Policy
3. Restrict Server Information Disclosure:
   • Disable version headers in the server configuration (e.g., Apache or Nginx).
4. Re-Scan After Fixing:
   • Run another scan to verify that vulnerabilities have been resolved.

Task 5: Advanced Features

1. Spidering the Target:
   • Use the spider tool to discover all linked pages and resources.
     • In the toolbar, click on Spider and enter the target URL.
2. Fuzzing Inputs:
   • Use the Fuzzer tool to test inputs for vulnerabilities.
     • Right-click on a request in the history tab and select Attack > Fuzz.
     • Add payloads and start the fuzzing process.
3. Using the API:
   • Automate scans with ZAP’s REST API.
     • Documentation available at: ZAP API Guide.

Best Practices

1. Run ZAP on Authorized Targets Only:
   • Ensure you have explicit permission to scan the target.
2. Combine Tools for Comprehensive Testing:
   • Use ZAP alongside other tools like Nikto, Burp Suite, or Nessus.
3. Document and Prioritize Findings:
   • Keep a record of vulnerabilities, their impact, and remediation status.
4. Educate Development Teams:
   • Train developers on secure coding practices to prevent vulnerabilities.

Key Takeaways

1. OWASP ZAP is a powerful tool for identifying and mitigating web application vulnerabilities.
2. Regular scans help maintain the security of web servers and applications.
3. Addressing ZAP’s findings reduces the risk of exploitation.

Troubleshooting Tips

1. ZAP Cannot Intercept HTTPS Traffic:
   • Ensure the ZAP certificate is installed in your browser.
   • Verify browser proxy settings.
2. Slow Scans:
   • Limit the scan scope to specific directories or parameters.
3. Missing Alerts:
   • Check the scan scope and ensure all relevant pages are included.
   • Use spidering to discover hidden or unlinked resources.

By completing this lab, you now understand how to use OWASP ZAP to identify vulnerabilities in web servers and secure them effectively.