2022 Annual Penetration Testing Intelligence Report. Read Now

25 March, 2021

Top 5 open-source tools for network vulnerability scanning

Organizations conduct vulnerability assessments for their networks to identify the existing vulnerabilities, weaknesses, and loopholes. The results of such an assessment can help a network administrator in understanding the security posture of their network and implement defensive measures against potential threats and vulnerabilities. So often, vulnerability assessments involve a network vulnerability scanner tool which can be open-source, closed-source, or a mixture of both. In this article, we take a look at popular open-source network vulnerability scanning tools.

1.    OpenVAS (http://www.openvas.org/)
OpenVAS stands for Open Vulnerability Assessment Scanner. It is a full-featured open-source vulnerability scanner with extensive scan coverage. It is maintained by Greenbone Networks since its first launch in 2009. As of July 2020, more than 50,000 network vulnerability tests are conducted on the OpenVAS framework. OpenVAS came into existence after Nessus stopped being an open-source tool and changed to a proprietary tool. Various plugins for OpenVAS are written using the Nessus Attack Scripting Language (NASL).
It relies on the client-server architecture where search, storage, and processing operations occur at the server-side. Network administrators, vulnerability scanners, and penetration testers use the client-side to configure scans and view reports. OpenVAS is built for all-in-one scanning and provides search capabilities for more than 26,000 CVEs.

Figure 1: OpenVAS in action
Figure 1: OpenVAS in action

2.    OpenSCAP

OpenSCAP has multiple components that focus on security tools, policy enforcement, and compliance with standards. It derives its name from the Security Content Automation Protocol (SCAP). SCAP is maintained by the National Institute of Standards and Technology. OpenSCAP is a collection of open-source tools for the implementation of the SCAP standard. One such tool that it features is a vulnerability scanner module. It comes with automated vulnerability scans to minimize the manual workload of a security team.

Figure 2: OpenSCAP user interface
Figure 2: OpenSCAP user interface

3.    Nmap

Nmap is an open-source network scanning tool for port scanning, service fingerprinting, and identifying operation system versions. While it is popularly known as a network mapping and port scanning tool, it comes with the Nmap Scripting Engine (NSE) that can help in the detection of misconfiguration issues and security vulnerabilities. It comes in a command-line interface (CLI) as well as a graphical user interface (GUI).
At the time of writing this article, the latest version of this tool is 7.90.

Figure 3: Nmap CLI
Figure 3: Nmap CLI

4.    Wireshark

Wireshark is a real-time network protocol analyzer that continuously scans network traffic for vulnerabilities and suspicious activities. It is available for multiple platforms such as Linux, Windows, and OS X. Over the years; it has become a crucial part of the security toolkits of organizations. It keeps a continuous check on a network’s traffic and converts binary data into a human-readable format with proper structuring. It supports more than two thousand network protocols, and hence, it is a useful tool for network management.

Figure 4: Wireshark
Figure 4: Wireshark

5.    Metasploit

Primarily known as an essential tool for penetration testers for delivering and executing payloads and exploits, Metasploit comes with inbuilt network scanning capabilities that may be useful for organizations. Before 2009, the Metasploit Framework (MSF) was available as an open-source tool. After its acquisition by Rapid7, the company introduced MSF as a commercial tool. However, it does have a free version available with limited features, and it is known as Community Edition. Premium versions are referred to as the Express Edition and the Pro Edition. The free version comes with an easy-to-use Java-based graphical user interface.

Figure 5: Scanning an entire network using the Metasploit Framework
Figure 5: Scanning an entire network using the Metasploit Framework

Ending notes

While open-source products have their dedicated advantages in terms of cost-effectiveness and a supportive community, they do not come with dedicated customer support that many organizations look forward to. Further, in our security testing engagements, we have often come across instances where open-source tools failed to detect a vulnerability that was detected by a commercial tool. We firmly believe that security testing must be a simplified experience for organizations. Based on this, we have built the BreachLock cloud platform to provide a single destination for fulfilling all security testing needs of our clients. Schedule a discovery call with our experts today!

Penetration Testing

Penetration Testing Service

Cloud Penetration
Testing Services

Network Penetration Testing

Application Penetration

Web Application
Penetration Testing

Social Engineering

Learn more about BreachLock. Read our

FAQ Page