[Learning] Penetration Testing a Database Server

[Learning] Penetration Testing a Database Server
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Introduction

Penetration testing a database server is a crucial step in identifying vulnerabilities that could be exploited by attackers. This guide will walk you through the process, tools, and commands necessary to perform a comprehensive penetration test on a database server.

Objectives:

  • Understand the methodology of penetration testing a database server.
  • Learn how to use common tools for database server testing.
  • Execute commands to discover, exploit, and report vulnerabilities.

Prerequisites

Before starting, ensure you have the following:

  • A Linux-based system (preferably Kali Linux) or any environment with necessary tools installed.
  • A database server set up for testing (MySQL, PostgreSQL, Oracle DB, etc.).
  • Network access to the database server.
  • Basic knowledge of SQL and networking concepts.

Tools Required:

  1. Nmap - For network scanning.
  2. Metasploit - For exploiting vulnerabilities.
  3. SQLMap - For automated SQL injection and database takeover.
  4. Hydra - For brute-forcing credentials.
  5. John the Ripper - For password cracking.
  6. Burp Suite - For intercepting web traffic (if applicable).
  7. Netcat - For simple communication and banner grabbing.

Step 1: Information Gathering

1.1. Network Scanning

Use Nmap to scan the target database server and identify open ports and services.

Command:

nmap -sV -p 1-65535 <target-ip>
  • -sV: Service version detection.
  • -p 1-65535: Scans all ports.

Output Interpretation:
Look for open ports commonly associated with databases:

  • MySQL: 3306
  • PostgreSQL: 5432
  • Oracle DB: 1521

1.2. Service Enumeration

Gather more details about the services running on identified ports.

Command:

nmap -sS -sV -A -p <port> <target-ip>
  • -A: Enables OS detection, version detection, script scanning, and traceroute.

Step 2: Vulnerability Analysis

2.1. Checking for Default Credentials

Check if the database server is using default credentials.

Using Hydra:

hydra -L userlist.txt -P passlist.txt -s <port> <target-ip> <service>
  • -L userlist.txt: File containing possible usernames.
  • -P passlist.txt: File containing possible passwords.
  • <service>: e.g., mysql, postgresql, etc.

2.2. SQL Injection Testing

Use SQLMap to test for SQL injection vulnerabilities in web applications that interact with the database.

Command:

sqlmap -u "http://<target-url>?id=1" --dbs
  • --dbs: Enumerate databases.

2.3. Exploiting Vulnerabilities with Metasploit

Search for available exploits in Metasploit's database and use them against the database server.

Commands:

msfconsole
search <database service>
use <exploit/path>
set RHOST <target-ip>
set RPORT <port>
exploit

2.4. Banner Grabbing

Use Netcat to grab the banner of the database service for potential vulnerability identification.

Command:

nc <target-ip> <port>

Observe the banner returned, which might reveal software version and other details.

Step 3: Exploitation

3.1. Privilege Escalation

If you gain access to the database, escalate privileges to obtain more control.

Example Command (MySQL):

GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost';

3.2. Data Exfiltration

Extract sensitive data to demonstrate the impact of the vulnerability.

Example Command (SQLMap):

sqlmap -u "http://<target-url>?id=1" --dump

3.3. Password Cracking

If you capture password hashes, crack them using John the Ripper.

Command:

john --wordlist=rockyou.txt hashes.txt

Step 4: Post-Exploitation

4.1. Clean Up

Ensure that no changes you made during testing persist on the target.

4.2. Reporting

Document all findings, including vulnerabilities found, exploitation steps, and recommendations for remediation.

Report Structure:

  • Executive Summary: Brief overview of findings.
  • Methodology: Steps taken during testing.
  • Vulnerabilities: List of vulnerabilities found.
  • Exploitation: Details of exploitation and data exfiltration.
  • Remediation: Suggestions for fixing the vulnerabilities.

Conclusion

Penetration testing a database server requires a systematic approach, using a variety of tools and techniques. By following the steps outlined in this guide, you can uncover and help mitigate potential security risks in database environments.