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
- 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
- OWASP ZAP is pre-installed on Kali Linux. To verify, run:
- Launch OWASP ZAP:
- Start ZAP from the terminal:
zaproxy
- Alternatively, open it from the applications menu.
- Start ZAP from the terminal:
- Set Up Browser Proxy:
- Configure your browser to route traffic through ZAP.
- Proxy settings:
- HTTP Proxy:
127.0.0.1
- Port:
8080
- HTTP Proxy:
- Proxy settings:
- Install the ZAP certificate in your browser for HTTPS interception.
- Configure your browser to route traffic through ZAP.
Task 2: Scanning a Web Server
- Identify the Target:
- Choose the target URL (e.g.,
http://<target_ip>
).
- Choose the target URL (e.g.,
- 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.
- 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.
- 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
- View Alerts:
- Navigate to the Alerts tab to see identified vulnerabilities.
- Alerts are categorized by severity (e.g., High, Medium, Low).
- 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.
- High: SQL Injection detected in
- Example output:
- Expand Alert Details:
- Click on an alert to view detailed information, including:
- Description of the issue.
- Steps to reproduce.
- Recommended remediation actions.
- Click on an alert to view detailed information, including:
Task 4: Remediating Vulnerabilities
- Fix High-Severity Issues First:
- Example: If SQL Injection is detected:
- Use parameterized queries to sanitize user input.
- Validate and escape all user inputs.
- Example: If SQL Injection is detected:
- Add Missing Security Headers:
- Configure the web server to include headers like:
X-Frame-Options: DENY
Content-Security-Policy
- Configure the web server to include headers like:
- Restrict Server Information Disclosure:
- Disable version headers in the server configuration (e.g., Apache or Nginx).
- Re-Scan After Fixing:
- Run another scan to verify that vulnerabilities have been resolved.
Task 5: Advanced Features
- 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.
- Use the spider tool to discover all linked pages and resources.
- 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.
- Use the Fuzzer tool to test inputs for vulnerabilities.
- Using the API:
- Automate scans with ZAP’s REST API.
- Documentation available at: ZAP API Guide.
- Automate scans with ZAP’s REST API.
Best Practices
- Run ZAP on Authorized Targets Only:
- Ensure you have explicit permission to scan the target.
- Combine Tools for Comprehensive Testing:
- Use ZAP alongside other tools like Nikto, Burp Suite, or Nessus.
- Document and Prioritize Findings:
- Keep a record of vulnerabilities, their impact, and remediation status.
- Educate Development Teams:
- Train developers on secure coding practices to prevent vulnerabilities.
Key Takeaways
- OWASP ZAP is a powerful tool for identifying and mitigating web application vulnerabilities.
- Regular scans help maintain the security of web servers and applications.
- Addressing ZAP’s findings reduces the risk of exploitation.
Troubleshooting Tips
- ZAP Cannot Intercept HTTPS Traffic:
- Ensure the ZAP certificate is installed in your browser.
- Verify browser proxy settings.
- Slow Scans:
- Limit the scan scope to specific directories or parameters.
- 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.