Nessus – Features, Installation, Benefits and More

Introduction

Nessus is a widely used open-source network scanner that is used for creating a cross-link between cyber security tools. Developed by Tenable Inc, nessus serves as a vulnerability scanner for penetration testing projects. It is an open-source network scanner that is designed to create a cross-link between security tools. Highly popular due to its diverse plugin database. Nessus is deployed for penetration testing and assessment of vulnerabilities susceptible to malicious attacks.

Features of Nessus

Here is a list of the major features of the cybersecurity tool:

• Discovering assets
• Scanning of networks
• Prioritisation
• Scaling of web applications
• Management of policies
• Scanning of vulnerabilities
• Scanning of web

How does Nessus work?

Nessus is segregated into two divisions: a client and a server named “Nessusd”. The “client part” offers instructions to server about the tests to run on specific target systems. The “server” part runs the tests as per the instructions. Here is a step-by-step guide on the operation of the cyber security tool:

Step 1 - Host Discovery:

The first step is to identify the network hosts, such as server, router, devices etc. Nessus deploys multiple techniques for the discovery phase like port scans. ping sweeps, and so on.


Step 2 - Port Scanning:

After discovery, the leading vulnerability scanner carries port scanning on the hosts to detect open ports. These open ports could be dangerous as they can be easily exploited to intrude into a network.


Step 3 - Service Identification:

Next, Nessus attempts to locate data about the services operating on the above-mentioned open ports. This step helps the tool comprehend the specific vulnerabilities of the target systems.


Step 4 - Assessment of vulnerabilities:

Then, Nessus runs an in-depth vulnerability assessment to detect potential issues like misconfigurations, weaknesses, etc. in the target system.


Step 5 - Prioritisation of risks:

Post assessment, Nessus lists the detected vulnerabilities based on their specific risk level. The most critical vulnerabilities are kept on the top since these demand immediate attention.


Step 6 - Reporting:

The next step is to create comprehensive reports about the vulnerabilities detected. The reports contain all the major data about each vulnerability such as potential impact, severity level, remediation measures, and so on. These assessment reports serve as a blueprint for security experts to gauge the security level of the target systems.


Step 7 - Consistent Monitoring:

Nessus continues with regular monitoring to detect new vulnerabilities so that remedial actions can be taken before it’s too late.


Step 8 - Compliance checking:

Nessus also shoulder the task of compliance auditing for user organisations. The tool makes sure the user systems comply with the set regulatory requirements and security standards.

Installation

Nessus is not preinstalled into Kali Linux, unlike other tools. The installation procedure of Nessus includes downloading Nessus and installing the Windows client. The installation screen option provides the user with different platforms to choose from where Nessus can run. You will also have to choose a compatible installation package. The tab of Target Selection provides you with the option to select the target host for scanning. The processes of installation can be carried out by the following steps:

• First, you need to download the Nessus package for the Debian framework. Then, set the platform as Linux-Debian-amd64
• After the download is complete, you have to open the Linux terminal. Then, you will navigate to the particular location where you have downloaded the Nessus
• Now you have to use the following command to install Nessus dpkg -i Nessus-10.4.1-debian9_amd64.deb
• After installation, you can use the following command to initiate the Nessus service systemctl start nessusd
• On the browser, you need to go to the https://kali:8834/ page, where it will display a warning
• Now you need to click on the Advanced option and click the Accept Risk and Continue
• If you want a free version, click on Nessus Essentials
• Next, you will be required to enter the name and email address to receive activation code via email

To run the scan, there must be a Nessus server that is already running on the machine. Next, you will start the Nessus client where you can enter the IP address of the server that you want to connect to.
Once you have entered the details, hit on ‘Start the scan’ button to begin scanning.
After scanning, Nessus client offers the list of identified vulnerabilities to help gauge the severity level. The client also suggests the users to fix the problem. Nessus allows the client side the ability to generate a graphical and comprehensive report in different formats.

Benefits of using Nessus

One of the main USPs of Nessus is that the cybersecurity tool doesn’t make any assumptions about server configuration. Thus, Nessus can detect a bunch of complicated vulnerabilities that other regular tools might miss out on. Nesus provides a user-friendly and fast way of finding as well as fixing vulnerabilities. This includes both virtualised and cloud-based resources. As per the data of April 2023, Nessus includes 76,000 Common Vulnerabilities and Exposures. Another benefit of using Nessus is that it offers 450 pre-configured templates. These templates are commonly used for configuration audits and vulnerability scanning.

Popular competitors of Nessus

Some of the most popular competitors of Nessus are:

• AlienVault USM
• Microsoft Defender for Cloud
• Intruder
• BurpSuite
• Acunetix by Invicti
• InsightVM (Nexpose)
• Invicti (formerly Netsparker)
• OpenVAS
• Amazon Inspector
• Tripwire Enterprise

Conclusion

In a nutshell, Nessus is one of the most trusted cyber security tools. It helps to identify and prioritise the various vulnerabilities that may create a risk to the digital environment of the organisation. At DataSpace Academy, our cyber security training course provides hands-on learning experience in Nessus and other cybersecurity tools. We are your trusted academic partner for building a strong career in cybersecurity.

Q1: What is Nessus?

Nessus is a leading remote cybersecurity scanner that scans computer networks for potential vulnerabilities. The tool also suggests crucial security measures to mitigate the vulnerabilities detected.

Q2: How does Nessus work in cybersecurity?

Nessus is a trusted name in the cyber security arsenal. This versatile tool shoulders a diverse range of functions to protect organisations from cyber threats- ranging from remote scanning to vulnerability assessment to suggestion of security measures, and more. The tool also helps user organisations to adhere to compliance regulations.

Q3: How does Nessus differ from its competitors?

One major factor that makes Nessus stand out is that, unlike its competitors, the tool doesn’t make preconceived assumptions about server configuration. Prior assumptions can be dangerous as these notions often prevent cybersecurity tools from detecting a bunch of vulnerabilities. But, as Nessus is free from these setbacks, it can detect most of those vulnerabilities that the majority of its competitors fail to detect.

Q4: Can Nessus be integrated with other security tools?

Yes, Nessus can be easily integrated with other security tools.