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Develop your own scripts for Nmap

The Scribe

Article from ADMIN 30/2015

By Holger Reibold

Nmap does a great job with standard penetration testing tasks, but for specific security analyses, you will want to develop your own test scripts. The Nmap Scripting Engine makes this possible.

For years, Nmap [1] has been essential to system administrators. There are virtually no alternatives to the classic tool for penetration testing. Out of the box, this tool already gives you more than 100 standard scripts. However, Nmap offers more than just the ability to run predefined scripts.

The Nmap Scripting Engine (NSE) gives you what is potentially the most powerful and flexible feature of all: the ability to run your own scripts and thus automate various scanning and analysis tasks. The scripts are based on the Lua programming language [2], which is easy to learn and perfect for developing test scripts. Nmap executes these scripts in parallel at a high speed and with great efficiency.

Nmap's core functions are network, version, and vulnerability analysis. NSE takes scanning with Nmap to the next level. For example, you can use the scan engine to identify SQL injection vulnerabilities and potential brute force attack vectors. With the help of NSE, you can create your own test scripts and modify existing ones. To help you keep track, the developers have divided the scripts into various categories. You need to be familiar with these to be able to assign your scripts correctly via the header configuration. Based on the category name, you can see the field of application. Table 1 summarizes the various types.

Table 1

Script Categories