Explore Pentesting the Easy Way: Using Nmap and Docker

In Part 1, we learned how to scan a server and interpret basic Nmap output. Now it’s time to simulate a real pentest — from detecting services to running actual vulnerability scans — all in a safe, legal, and local environment using Docker. No signup. No cost. Just you, your terminal, and some powerful open-source tools. What We'll Do We'll spin up a deliberately insecure web application (DVWA) using Docker and use Nmap to: Find which ports are open on a computer or server See what programs (services) are running and which versions they are Look for known security issues (vulnerabilities) Understand and make sense of the scan results like a real ethical hacker Step 1: Set Up the Vulnerable App (DVWA) We’re using DVWA (Damn Vulnerable Web Application), a popular training ground for beginner pentesters. Requirements: Docker installed on your machine Nmap installed Start DVWA with Docker: docker run -d -p 8888:80 vulnerables/web-dvwa This command will: Download the DVWA image (if not already present) Run it inside a container Expose the web app on your local machine at http://localhost:8888 When opening http://localhost:8888 you will see something like this Step 2: Identify the Service and Version Let’s start with a basic scan to see what’s running: nmap -sV -p 8888 127.0.0.1 This command tells Nmap to: -sV: Detect service versions -p 8888: Focus only on port 8888 (where our app runs) Sample Output: PORT STATE SERVICE VERSION 8888/tcp open http Apache httpd 2.4.25 ((Debian)) From the above output we can understand: What is running: a web server Which server: Apache Which version: 2.4.25 (Debian build)

Apr 12, 2025 - 21:35

Explore Pentesting the Easy Way: Using Nmap and Docker

In Part 1, we learned how to scan a server and interpret basic Nmap output. Now it’s time to simulate a real pentest — from detecting services to running actual vulnerability scans — all in a safe, legal, and local environment using Docker.

No signup. No cost. Just you, your terminal, and some powerful open-source tools.

What We'll Do

We'll spin up a deliberately insecure web application (DVWA) using Docker and use Nmap to:

Find which ports are open on a computer or server
See what programs (services) are running and which versions they are
Look for known security issues (vulnerabilities)
Understand and make sense of the scan results like a real ethical hacker

Step 1: Set Up the Vulnerable App (DVWA)

We’re using DVWA (Damn Vulnerable Web Application), a popular training ground for beginner pentesters.

Requirements:

Docker installed on your machine
Nmap installed

Start DVWA with Docker:

docker run -d -p 8888:80 vulnerables/web-dvwa

This command will:

Download the DVWA image (if not already present)
Run it inside a container
Expose the web app on your local machine at http://localhost:8888

When opening http://localhost:8888 you will see something like this

Step 2: Identify the Service and Version

Let’s start with a basic scan to see what’s running:

nmap -sV -p 8888 127.0.0.1

This command tells Nmap to:

-sV: Detect service versions
-p 8888: Focus only on port 8888 (where our app runs)

Sample Output:

PORT     STATE SERVICE VERSION
8888/tcp open  http    Apache httpd 2.4.25 ((Debian))

From the above output we can understand:

What is running: a web server
Which server: Apache
Which version: 2.4.25 (Debian build)