For this project, we use the Nessus vulnerability scanner to check a host for security issues. First, we walk through the installation and setup process, and then we look at how to scan and interpret the results.

Nessus can be downloaded for free from www.nessus.org. Both the client and the server for Nessus 3 are available for a variety of operating systems, including Windows and Linux. The Nessus 2 client is only available for UNIX-based operating systems.

For this project, we use Nessus 3 for Windows. Installation is very straightforward and is similar for different operating systems. At the end of the installation, the Nessus Plugin Update Wizard runs to check for the latest updates online.

After installing Nessus, you can configure the server to listen on any port or interface. By default, it listens on port 1241 of 127.0.0.1. Unless it needs to be accessible to other hosts, it is a good idea to keep it listening on the loopback address. If you need to make Nessus available to other hosts, use the Scan Server Configuration utility.You can also add accounts for remote users with the Nessus User Management tool.

To scan a host or group of hosts, run the Tenable Nessus Security Scanner and click on Start Scan Task.There are a variety of options for specifying one or more hosts to scan, but for this project we keep it simple and put a single host name or IP...