Book Image

Nmap 6: Network Exploration and Security Auditing Cookbook

Book Image

Nmap 6: Network Exploration and Security Auditing Cookbook

Overview of this book

Nmap is a well known security tool used by penetration testers and system administrators. The Nmap Scripting Engine (NSE) has added the possibility to perform additional tasks using the collected host information. Tasks like advanced fingerprinting and service discovery, information gathering, and detection of security vulnerabilities."Nmap 6: Network exploration and security auditing cookbook" will help you master Nmap and its scripting engine. You will learn how to use this tool to do a wide variety of practical tasks for pentesting and network monitoring. Finally, after harvesting the power of NSE, you will also learn how to write your own NSE scripts."Nmap 6: Network exploration and security auditing cookbook" is a book full of practical knowledge for every security consultant, administrator or enthusiast looking to master Nmap. The book overviews the most important port scanning and host discovery techniques supported by Nmap. You will learn how to detect mis-configurations in web, mail and database servers and also how to implement your own monitoring system. The book also covers tasks for reporting, scanning numerous hosts, vulnerability detection and exploitation, and its strongest aspect; information gathering.
Table of Contents (18 chapters)
Nmap 6: Network Exploration and Security Auditing Cookbook
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
References
Index

Discovering UDP services


UDP services are often ignored during penetration tests, but good penetration testers know that they frequently reveal important host information and can even be vulnerable and used to compromise a host.

This recipe shows how to use Nmap to list all open UDP ports on a host.

How to do it...

Open your terminal and type:

#nmap -sU -p- <target>

The output follows Nmap's standard format:

# nmap -sU -F scanme.nmap.org

Nmap scan report for scanme.nmap.org (74.207.244.221)
Host is up (0.100s latency).
Not shown: 98 closed ports
PORT    STATE         SERVICE
68/udp  open|filtered dhcpc
123/udp open          ntp

How it works...

The argument -sU tells Nmap to launch a UDP scan against the target host. Nmap sends UDP probes to the selected ports and analyzes the response to determine the port's state. Nmap's UDP scanning technique works in the following way:

  1. A UDP packet is sent to the target with an empty UDP payload unless one is specified in the file nmap-payloads.

  2. If the...