Best Open Source Cybersecurity Tools

There are many open source cybersecurity tools that IT security professionals can use to identify vulnerabilities before they are discovered and exploited by hackers. Using commercial open source cybersecurity tools will greatly improve an organization’s security posture and will protect against hacks and data breaches. There are many tools available and finding the right tools to use can require considerable research. Therefore, to save you some time in your search, we have listed 10 of the best open source cybersecurity tools for you to consider adding to your IT security arsenal.

Metasploit Framework

One of the best open source cybersecurity tools available is the Metasploit Framework. This is an exploitation and vulnerability validation tool that can be used for penetration testing to identify known and open vulnerabilities before they are found by hackers. This is an extremely powerful and useful tool that is used by most professional penetration testers to identify vulnerabilities in clients’ networks due to the sheer extent of its capabilities.

Metasploit automates the different stages of penetration testing and can perform sophisticated network attacks including cross-site scripting, website cloning, and phishing attacks. It can be used for auditing and network port scanning and has an auto-exploitation feature that cross-references open services, fingerprints, and vulnerability references to find appropriate exploits. It can also be used by IT security teams to maintain and manage their security workflows.


Snort is one of the most powerful open source intrusion detection systems (IDS) available and also one of the most popular. The solution is maintained by Cisco and can be used by security teams to capture and analyze network traffic to identify intrusion attempts in real-time. Security agencies such as the Cybersecurity and Infrastructure Security Agency (CISA) often release Snort signatures associated with Advanced Persistent Threat (APT) actors and ransomware gangs that rapidly identify attacks in progress.

One of the main advantages of Snort over other IDS tools is it can be used in 3 modes: As a full IDS, a packet logger, and network sniffer. Snort can be used for detecting web vulnerabilities such as stealth scans, semantic URL attacks, buffer overflows, and OS fingerprinting.

The solution is a great option for use in an automated security system or in conjunction with other security products. The solution is being actively developed, and because it is so extensively used, there is an active online community of users providing feedback and advice. The solution is also easy to set up and use, even by individuals new to IDS systems and network testing, which is why it is one of the best open source cybersecurity tools available.


Nmap is an open source security software tool that is used for network scanning to check for open ports, vulnerable services, and OS detection and is popular with IT security professionals, penetration testers, and hackers. Nmap is one of the best open source cybersecurity tools for offensive and defensive security and many hackers use the tool to obtain the information they need to hack into systems.

The tool maps networks and ports, uses scripts to detect security issues, and collects raw data and determines host type, operating system, and intrusion detection mechanisms in place. Nmap will identify open and filtered ports, all hosts available within a network by sending TCP/IP requests and will return sensitive information about remote users. The tool has been developed specifically for scanning large networks but can be used on single hosts. It is also possible to write customized scripts in Lua via the Nmap scripting engine.

Cuckoo Sandbox

Cuckoo Sandbox is a user-friendly open source cybersecurity tool for securely analyzing suspicious files to discover malicious actions that will be triggered if the file is opened by a user within your network environment. Cuckoo Sandbox is one of the best open source cybersecurity tools for automated malware analysis and is used to trick malware into thinking it is infecting a genuine host. Any files can be analyzed by this open source cybersecurity tool and, in a matter of minutes, it can identify relevant Indicators of Compromise (IOC’s) such as network connections, suspicious Application Programming Interface (API) use, and any files attempted to be saved to disk.

In addition to testing files, the tool can be used to perform an analysis of websites and network traffic. The solution will also perform an analysis of any software to determine if attempts are being made to install files outside of permitted areas, allowing fake software and compromised installers to be identified to prevent the installation of malware.


Any list of the best open source cybersecurity tools should include a password manager. Password managers are used to create and securely store complex passwords that are resistant to brute force attacks.

Bitwarden is an excellent, cost-effective choice for businesses that makes it quick and easy for employees to create unique, strong passwords for each of their accounts. The solution includes a password generator than can be configured to suggest strong passwords based on the organization’s password complexity requirements.

The solution is open source, operates under the zero-knowledge model, and has undergone an independent 3rd party security audit. Features include end-to-end encryption, secure password sharing, cross-platform accessibility, health reports of password vaults, detailed event logging to track access to sensitive data, and flexible integrations using SSO authentication, directory services, or powerful APIs. There is also the option of cloud hosting for convenience or self-hosting for total control.


Nikto is a popular, free open source web server scanner used by many IT security professionals to identify vulnerabilities and misconfigurations in web servers. The solution identifies installed web servers and software and scans for more than 6,700 potentially harmful programs and dangerous files and CGIs. This open source cybersecurity tool will identify outdated versions of servers and version-specific issues with servers.

Nikto can be used to check for misconfigurations that leave web servers vulnerable and configuration issues such as multiple index files and HTTP server options. It will also capture and print any cookies it receives.

Nikto is a lightweight, Perl-based command-line tool that runs on virtually all Unix-like systems and has proven popular since its release with pen testers. It is not a stealthy tool, instead it has been developed to find security issues in the shortest possible time.


Wfuzz (web fuzzer) is an open source penetration testing tool that is used for brute-forcing web applications and automating web application security assessments. Wfuzz allows a payload to be injected into any field of an HTTP request – thus allowing pen testers to simulate a wide range of complex web security attacks on various components – and includes parameters such as HTTP, GET, and POST, authentication, and web forms, etc. The tool is often used to expose vulnerabilities such as SQL and LDAP injections and cross-site scripting. The tool will export results to HTML or can be used in combination with more powerful Linux vulnerability scanners.

Wfuzz is lightweight, versatile, and supported by plugin, and makes it onto our list of the best open source cybersecurity tools due to its flexibility. Building Python-based plugins for this open source tool is a quick and simple process, and there is an active community of users and excellent documentation to get the most out of the solution.


Ettercap is one of the best open source cybersecurity tools for conducting man-in-the-middle attacks on LAN. The tool is free to use and is ideal for conducting IP-based, MAC-based, ARP-based, and PublicARP-based attacks, with features such as HTTPS support, OS fingerprinting, passive scanning, and DNS hijacking. The tool can be easily configured to look for specific types of vulnerabilities to determine how an environment responds to each attack.

Ettercap will collect huge amounts of information about the network and all devices connected to it and is a useful tool for network protocol analysis and security auditing, providing users with great visibility into their network. Ettercap can be used to intercept traffic on a network segment, for content filtering on the fly, capturing passwords, and eavesdropping against several protocols. Ettercap is supported by plugins which provide a wide range of features for network and host analysis.

Infection Monkey

Infection Monkey is a free, open source attack simulation tool that is used for testing network security to assess resiliency to attacks where a hacker has successfully breached the perimeter defenses.

The tool will scan the network for open ports and will fingerprint machines using several different network protocols. Once accessible machines have been identified it will self-propagate across the data center and infect those machines and report back to the “Monkey Island” server, which is used to control and visualize the infection process inside the data center. The tool produces detailed data about the attack, including the vulnerabilities that were exploited, and the effect vulnerable segments have on overall network security to allow security teams to identify areas where security needs to be strengthened.


VeraCrypt is a free, easy-to-use, open source encryption tool that can be used for full-disk encryption on any Windows PC. Once configured, the entire disk is encrypted, with the user required only to enter the encryption password on boot. The tool can also be used to encrypt partitions and, since it is cross-platform, it can be used on the full range of machines without compatibility problems.

VeraCrypt stands out as one of the best open source cybersecurity tools for encryption due to advanced security features, including allowing encryption of hidden volumes and operating systems with support provided for multiple encryption algorithms, allowing users to encrypt and store files as they see fit.

VeraCrypt is an on-the-fly encryption tool, meaning data is automatically encrypted and decrypted when it is loaded or saved, which makes it ideal for any portable storage device that could be easily stolen. VeraCrypt is an off shoot of the discontinued TrueCrypt project that was first released in 2013, with many security improvements made to optimize it for use on modern PCs.