Specifications

 CVE Compatible – Most plugins link to CVE for administrators to retrieve further information on published

vulnerabilities. They also frequently include references to Bugtraq (BID), OSVDB, and vendor security alerts.

 Plugin Architecture – Each security test is written as an external plugin and grouped into one of the plugin

families. This way, you can easily add your own tests, select specific plugins, or choose an entire family without

having to read the code of the Nessus server engine, nessusd. The complete list of the Nessus plugins is

available at http://www.nessus.org/plugins/index.php?view=all.

 NASL – The Nessus scanner includes NASL (Nessus Attack Scripting Language), a language designed

specifically to write security tests easily and quickly.

 Up-to-date Security Vulnerability Database – Tenable focuses on the development of security checks for newly

disclosed vulnerabilities. Our security check database is updated on a daily basis and all the newest security

checks are available at http://www.tenable.com/plugins/index.php?view=newest.

 Tests Multiple Hosts Simultaneously – Depending on the configuration of the Nessus scanner system, you can

test a large number of hosts concurrently.

 Smart Service Recognition – Nessus does not expect the target hosts to respect IANA assigned port numbers.

This means that it will recognize a FTP server running on a non-standard port (e.g., 31337) or a web server

running on port 8080 instead of 80.

 Multiple Services – If two or more web servers are run on a host (e.g., one on TCP port 80 and another on TCP

port 8080), Nessus will identify and test all of them.

 Plugin Cooperation – The security tests performed by Nessus plugins cooperate so that unnecessary checks

are not performed. If your FTP server does not offer anonymous logins, then anonymous login related security

checks will not be performed.

 Complete Reports – Nessus will not only tell you what security vulnerabilities exist on your network and the risk

level of each (Info, Low, Medium, High, and Critical), but it will also tell you how to mitigate them by offering

solutions.

 Full SSL/TLS Support – Nessus has the ability to test services offered over SSL such as HTTPS, SMTPS,

IMAPS, and more.

 Smart Plugins (optional) – Nessus has an “optimization” option that will determine which plugins should or

should not be launched against the remote host. For example, Nessus will not test sendmail vulnerabilities

against Postfix.

 Non-Destructive (optional) – Certain checks can be detrimental to specific network services. If you do not want

to risk causing a service failure on your network, enable the “safe checks” option of Nessus, which will make

Nessus rely on banners rather than exploiting real flaws to determine if a vulnerability is present.

 Open Forum – Found a bug? Questions about Nessus? Start a discussion at https://discussions.nessus.org/.

Prerequisites

Tenable recommends the following hardware depending on how Nessus is used. Note that these resources are

recommended specifically for running Nessus. Additional software or workload on the machine warrants additional

resources.

Scenario

CPU/Memory

Disk Space

Nessus scanning smaller networks

CPU: 1 Dual-core 2GHz Intel CPU (dual-core Intel® for Mac

OS X)

30 GB