Web Application Penetration Testing | Penetration Testing

Introduction

Web Application Penetration Testing is a methodical approach to testing the security of a web application by simulating an attack from a malicious hacker. The aim is to identify and exploit vulnerabilities to determine their impact on the application and its data.

Setting Up the Environment

Before beginning penetration testing, it's essential to set up a controlled environment. This includes:

Installing necessary software tools (e.g., Burp Suite, OWASP ZAP, Metasploit).
Configuring a test environment that mirrors the production environment.
Ensuring you have legal authorization to test the application.

Reconnaissance

The first step in penetration testing is reconnaissance, where you gather as much information as possible about the target application. This includes:

Discovering subdomains using tools like sublist3r.
Gathering information on technologies used, such as the web server, database, and frameworks.
Identifying endpoints and API documentation.

Example:

Using sublist3r to find subdomains:

sublist3r -d example.com

Output:

subdomain1.example.com
subdomain2.example.com
subdomain3.example.com

Scanning

Scanning involves using automated tools to find vulnerabilities in the web application. Common tools include:

Burp Suite
OWASP ZAP
Acunetix

Example:

Using OWASP ZAP to scan for vulnerabilities:

1. Open OWASP ZAP.
2. Enter the target URL in the URL to attack field.
3. Click on 'Attack' to start the scan.

Output:

High Risk Vulnerabilities:
- SQL Injection
- Cross-Site Scripting (XSS)

Medium Risk Vulnerabilities:
- Missing Security Headers

Exploitation

Exploitation involves taking the vulnerabilities discovered during scanning and attempting to exploit them to demonstrate their impact. Common vulnerabilities include:

SQL Injection
Cross-Site Scripting (XSS)
Remote Code Execution (RCE)

Example:

Exploiting an SQL Injection vulnerability:

1. Identify a vulnerable input field.
2. Inject a malicious SQL payload: ' OR '1'='1
3. Observe the system's response to confirm the vulnerability.

Output:

Original Query:
SELECT * FROM users WHERE username='admin' AND password='password';

Injected Query:
SELECT * FROM users WHERE username='' OR '1'='1' AND password='';

Post-Exploitation

After successfully exploiting vulnerabilities, the next step is post-exploitation. This phase involves:

Maintaining access to the compromised system.
Escalating privileges to gain deeper access.
Exfiltrating sensitive data.

Reporting

The final step in penetration testing is reporting. This involves documenting the findings, including:

A summary of the discovered vulnerabilities.
The potential impact of each vulnerability.
Recommendations for remediation.

Example:

Sample report structure:

1. Executive Summary
2. Scope of Testing
3. Methodology
4. Findings
    - Vulnerability 1
        - Description
        - Impact
        - Proof of Concept
        - Remediation
    - Vulnerability 2
        - Description
        - Impact
        - Proof of Concept
        - Remediation
5. Conclusion

Conclusion

Web Application Penetration Testing is a crucial process in identifying and mitigating security risks in web applications. By systematically testing and exploiting vulnerabilities, security professionals can secure applications against real-world attacks.