25 Best Open Source Security Tools To Protect Your System

Security tools are computer programs that allow us to find vulnerabilities in software. Malicious users use them to gain unauthorized access to information systems, enterprise networks, or even personal workstations. Security researchers, on the other hand, use these tools to find bugs in software so that companies can patch them before exploitation could take place. There is a wide range of open source security tools that are used by both the bad guys and penetration testing professionals. Today, we have compiled a list of 25 such programs that have widespread usage in computer security and other related fields.

Open Source Security Tools for InfoSec Professionals

Some security tools are used extensively for escalating security privileges, whereas there are many tools that aim to provide defensive capabilities against such breaches. Our editors have chosen their picks from both sides so that you can have a clear understanding of standard security-related problems.

1. Metasploit

The Metasploit Project is, without any doubt, one of the best security projects of modern times. At its heart, sits the Metasploit framework, an extremely powerful tool that allows users to manage and maintain their security workflows at ease. The core solution is available freely in GitHub.

So, interested users can view the source themselves and gain a better understanding of how it works. Most penetration testers use this framework to carry out professional security auditing tasks due to its immense number of features and capabilities.

Features of Metasploit

• Metasploit helps security professionals in automating the various stages of penetration testing through its robust modules.
• It allows users to perform sophisticated network attacks such as website cloning, cross-site scripting, and phishing campaigns.
• The Metasploit framework is written using the Ruby scripting language, which makes it very easy to extend this tool.
• Enterprises can opt-in for the premium version of Metasploit for ensuring maximum operability and technical support.

Download Metasploit

2. Nmap

Nmap is a compelling network scanner that is widely used by security professionals and malicious users. It allows us to scan hosts for open ports, vulnerable services, and OS detection. Most hackers will use Nmap at the starting phase of their attack since it provides them the essential information required to take down remote systems. Although it is a command-line tool, there is a nice GUI interface called Zenmap. Additionally, a large number of Nmap commands help people discover sensitive information about remote users and networks.

Features of Nmap

• Nmap enables users to discover available hosts in a computer network by sending TCP/IP network requests.
• It makes it easy to enumerate over port lists and identify whether certain ports are open or filtered.
• Security professionals can obtain important information like OS version, running services, and the presence of IDS mechanisms.
• The NSE(Nmap Scripting Engine) allows users to write customized scripts using the Lua programming language.

Download Nmap

3. OSSEC

OSSEC or Open Source Host-based Intrusion Detection System is a modern-day IDS that helps professionals discover security problems in enterprise servers. It allows users to analyze system logs, perform integrity checks, monitor the Windows registry, and many more. OSSEC also enables us to find the presence of any potential rootkits and provides excellent alerting mechanisms. Many corporations have started to use OSSEC for detecting hard to catch problems due to its diverse capabilities and rich feature set.

Features of OSSEC

• OSSEC allows security professionals to maintain industry compliances by detecting unauthorized changes in system files and configurations.
• The Active Response feature of OSSEC makes sure immediate steps are taken as soon as a security vulnerability arises.
• It provides real-time alerts on intrusion detection and can be integrated with existing SIM(Security Incident Management) solutions very easily.
• The open-source nature of this project allows developers to customize or modify the software as they require.

Download OSSEC

4. OWASP ZAP

OWASP ZAP or Zed Attack Proxy is an excellent security scanner program for modern web applications. It is developed and maintained by a team of internationally recognized security experts. Zed Attack Proxy allows admins to find a large number of common security vulnerabilities. It is written using the Java programming language and offers both graphical and command-line interfaces. Moreover, you don’t need to be a certified security professional for using this software since it is very straightforward for even absolute beginners.

Features of OWASP ZAP

• Zed Attack Proxy can find security flaws in web applications during both the development phase and testing phase.
• It exposes compelling REST-based APIs which allow admins to automate complex security scanning workflows at ease.
• The ZAP marketplace offers a large number of powerful add-ons that can enhance the functionality of this program.
• Its open source license allows developers to customize this Linux vulnerability scanner without any legal hassles.

Download OWASP ZAP

5. Security Onion

Security Onion is one of the best security platforms for enterprise environments due to its rich feature set and powerful monitoring tools. It’s a standalone Linux distribution developed specifically for intrusion detection, log management, and security assessment. Security Onion comes pre-equipped with a large number of open source security tools like NetworkMiner, Logstash, and CyberChef. Our editors really liked this security-focused Linux distribution due to its ease of use. It is the perfect solution for businesses that are looking for enforcing security standards.

Features of Security Onion

• It is a full-fledged Linux distribution aimed at enterprise network security, not a standalone scanning application.
• Security Onion is very easy to install and set up even for people with little or no prior experience of security tools.
• It can capture and analyze full network packets, session data, transaction data, network logs, and HIDS alerts.
• The open-source nature of this Linux environment makes it easy to customize based on enterprise requirements.

Download Security Onion

6. OpenVAS

OpenVAS is a security testing suite that consists of a large number of services and tools used in vulnerability assessment. It started as a fork of Nessus but has since grown into a full-fledged vulnerability scanning framework. One excellent selling point of this software suite is the ability to manage demanding security services from a web-based dashboard. OpenVAS works very well when it comes to locating flaws in network servers and infrastructures. Moreover, its open-source nature makes sure users can utilize the framework without any limit.

Features of OpenVAS

• The standard web-based dashboard of this Linux vulnerability scanner is very intuitive and easy to operate.
• It provides in-depth information about the vulnerabilities it finds alongside its CVSS score and risk rating.
• OpenVAS also offers excellent recommendations on how to overcome security vulnerabilities based on its impact.
• Third-party developers can easily extend this framework using the Nessus Attack Scripting Language or NASL.

Download OpenVAS

7. Wireshark

Wireshark is an open-source packet analyzer that allows users to view network streams in exceptional detail. It is one of the best open source security tools for network troubleshooting and analysis due to its practical use cases. Malicious users often use Wireshark to capture network packets and analyze them for usable sensitive information. It is a multi-platform application with ready-made packages for different Linux and BSD distributions. Overall, it is a future-proof upgrade for people who are working with tools like tcpdump or tshark.

Features of Wireshark

• Wireshark can capture live packets and analyze them for obtaining readable information like plaintext passwords.
• It can save packets, import them from saving files, filter them, and even colorize them for a better visual representation.
• Wireshark is written using C and C++ programming languages, which makes it extremely fast and portable.
• It comes under the open-source GNU GPL license, which allows users to view the source and make further customizations.

Download Wireshark

8. Nikto

Nikto is a compelling web server scanner that has been gaining tremendous popularity since its release. It is a command-line tool that allows admins to check for server misconfigurations, outdated packages, and buggy CGIs, among many more. The lightweight nature of Nikto has mainly contributed to its success. Many modern penetration testers use Nikto as a replacement for larger server scanners like Zed Attack Proxy (ZAP). Nikto is written using Perl and runs flawlessly on most Unix-like systems.

Features of Nikto

• Nikto comes with built-in support for HTTP proxies, OpenSSL, LibWhisker’s IDS encoding, and integration with Metasploit.
• Its robust template engine makes it easy to create custom scan reports and save them in HTML, plaintext, or CSV documents.
• Admins can easily deploy Nikto as a docker container using pre-built container images or with custom configurations.
• The freely available source code of Nikto allows developers to extend or modify the software as they see fit.

Download Nikto

9. W3af

W3af is a highly capable security testing framework for modern-day web applications. It is an open-source project written in Python and offers excellent customization opportunities for developers. W3af can find more than 200 types of security vulnerabilities including, SQL injections, cross-site scripting, CSRF, OS commanding, and stack-based buffer overflows. It is a truly cross-platform software that is very extremely easy to extend. This is one of the main reasons behind its growing popularity among security professionals.

Features of W3af

• W3af is extremely extendible and offers a large number of pre-built plugins for added functionalities.
• It comes with a centralized knowledge base that stores all vulnerabilities and information disclosures effectively.
• The powerful fuzzing engine of W3af allows users to inject payloads into any component of an HTTP request.
• Users can receive the output of their web scans in Linux command shells, data files, or directly via email.

Download W3af

10. Wapiti

Wapiti is another extremely powerful security scanner for web-based applications. It performs black-box scans to get the list of all possible URLs, and once successful, it will try to find vulnerable scripts by injecting payloads to them. Thus, it also acts like a Fuzzer. Wapiti can be used for detecting several types of web vulnerabilities such as XSS, Server Side Request Forgery(SSRF), database injection, and file disclosures. Overall, it is a very capable program that can find a large number of bugs pretty easily.

Features of Wapiti

• Wapiti allows several types of authentication methods and the ability to suspend or resume scans anytime.
• It can scan web apps very fast and provides different levels of verbosity based on user preference.
• Users may choose to highlight any reported vulnerabilities by color-coding them in their Linux terminal.
• Wapiti leverages the Nikto vulnerability database for pinpointing the presence of potentially risky files.

Download Wapiti

11. CipherShed

CipherShed is a modern-day encryption software which started out as a fork of the now-defunct TrueCrypt Project. It aims to provide top-notch security to your sensitive data and can be used for protecting both personal and enterprise systems. This cross-platform application runs smoothly on all major operating systems including, Linux and FreeBSD. Moreover, the open-source nature of this project makes sure developers can easily access and modify the source code if they intend to.

Features of CipherShed

• CipherShed comes with an intuitive GUI interface, which makes operating this software very easy for professionals.
• It is extremely lightweight and allows users to create secure containers holding sensitive information very fast.
• CipherShed allows users to unmount the encrypted volumes for moving them someplace safe.
• The encrypted drives can be transported between different systems without any compatibility issues.

Download CipherShed

12. Wfuzz

Wfuzz is one of the best open source security tools for brute-forcing web-based applications effectively. It is developed using Python and provides a simple command-line interface for managing the program. Wfuzz can expose several types of vulnerabilities, including SQL injections, LDAP injections, and cross-site scripting.

Penetration testers often use this tool for brute forcing HTTP GET and POST parameters, as well as fuzzing web forms. So, if you’re looking for a lightweight vulnerability scanner for web apps, Wfuzz can be a viable solution.

Features of Wfuzz

• It can perform HEAD scans for faster resource disclosures and supports multiple encoding methods for payloads.
• Wfuzz comes with in-built support for HTTP proxies, SOCK, cookie fuzzing, time delays, and multi-threading.
• Users can save the output results in HTML files or export them to more powerful Linux vulnerability scanners.
• It offers excellent documentation for helping users get up and running as fast as possible.

Download Wfuzz

13. OSQuery

OSQuery is a modern-day system’s application that can be used for instrumenting, monitoring, and analyzing changes in operating systems. It is developed by the engineering team at Facebook and relies on the SQL querying language for viewing changes in security events.

Admins can use OSQuery for monitoring low-level system details like running processes, network streams, kernel modules, hardware changes, and even file hashes. The source code of this tool is freely available at GitHub. So, developers can customize it for adhering to enterprise requirements.

Features of OSQuery

• It exposes a modern, interactive console called osqueryi that allows users to try robust queries and explore system details.
• OSQuery comes with dozens of in-built tables that accelerate the diagnosis of system changes and performance issues.
• The powerful monitoring daemon osqueryd enables admins to schedule execution queries for large-scale infrastructures.
• OSQuery is built using modular codebases that guarantee top-notch performance and provides excellent documentation.

Download OSQuery

14. SonarQube

SonarQube is one of the best open source security testing tools for security professionals due to its rich feature set and excellent performance. It is written using the Java programming language and allows researchers to find some common threats to web applications.

SonarQube can detect cross-site scripting vulnerabilities, Denial of Service (DOS) attacks, and SQL injections, among others. It can review websites for coding problems and integrates well with tools like Jenkins. Overall, it is a helpful tool for both security practitioners and web app developers.

Features of SonarQube

• SonarQube can find hard-to-catch logical errors in web applications using robust static code analysis rules.
• Although written in Java, it can review apps written in more than twenty-five different programming languages.
• It can also be used for reviewing project repos and integrates easily with platforms like GitHub and Azure DevOps.
• SonarQube offers several paid editions for enterprises and developers alongside its open-source version.

Download SonarQube

15. Snort

Snort is a powerful intrusion detection system that is currently being maintained by Cisco. It allows security testers to capture and analyze network traffic in real-time. It can detect several types of web vulnerabilities, including but not limited to stealth scans, semantic URL attacks, buffer overflows, and OS fingerprinting. It offers excellent documentation for people who are new to packet analyzing in general. So you can easily set it up and start testing for network flaws.

Features of Snort

• Snort can be configured in three different modes, as a sniffer, packet logger, or network intrusion detection mechanism.
• It comes under the permissive GNU GPL license, so developers can easily add their own modifications to this software.
• Snort integrates perfectly with several third-party reporting and analysis tools, including BASE, Snorby, and Sguil.
• Cisco rolls out newer features and bug fixes for this intrusion detection system pretty often.

Download Snort

16. VeraCrypt

VeraCrypt is certainly one of the best open source security tools for protecting sensitive data. It’s an open-source disc encryption platform that allows users to encrypt their Linux partitions on the fly. Like CipherShed, it is also a fork of the now-discontinued TrueCrypt project.

VeraCrypt improves the performance issues faced by many encryption software by developing the runtime using C, C++, and Assembly languages. Moreover, it is entirely cross-platform. So, you can use this tool on all of your machines without facing compatibility issues.

Features of VeraCrypt

• VeraCrypt works by creating virtual encrypted discs which can be mounted normally on the Linux file system.
• It has in-built support for parallelization and pipelining, which makes sure disc operations are not slowed down.
• VeraCrypt provides some extremely advanced security features like hidden volumes and hidden operating systems.
• It offers several encryption formats, including transparent encryption, automatic encryption, and real-time encryption.

Download VeraCrypt

17. Moloch

Moloch is one of the most promising open source security testing tools in recent times. It is a robust platform that facilitates the capturing of TCP/IP packets and enables users to manage these packets from a conventional database management system. This open-source project has been gaining popularity among many testers due to its simplistic approach to mitigate common network threats. Moloch also offers extensive, high-quality documentation for helping people get started with this application.

Features of Moloch

• Moloch is extremely scalable and can be deployed on enterprise clusters that tackle multiple gigabits of traffic per second.
• It exposes a robust set of APIs that makes it easy to integrate Moloch with other open source security tools at ease.
• Admins can easily export their search results as PCAP or CSV documents using the centralized GUI interface.
• Moloch is entirely cross-platform and offers pre-built binaries for several Linux distributions, including Ubuntu.

Download Moloch

18. Aircrack-ng

Aircrack-ng is the de-facto software suite used by hackers to bypass wireless network authentication. It is a collection of open source security tools, which include a sniffer, password cracker, and analysis tools, among others. Aircrack-ng allows users to crack WEP and WPA/WPA-2 credentials using several methods such as statistical analysis and dictionary attacks. As with other security tools, a lot of professionals also use Aircrack-ng for checking the integrity of wireless networks.

Features of Aircrack-ng

• It supports several types of network attacks, including replay attacks, packet injection, de-authentication, and more.
• All tools provided by Aircrack-ng is controlled through a versatile command-line interface which supports heavy scripting.
• Aircrack-ng is readily available on most Linux distributions and is also fairly easy to compile from the source.
• The open-source codebase of this application suite makes it easy to inspect and add newer features.

Download Aircrack-ng

19. Tcpdump

Tcpdump is a simple but extremely powerful packet sniffer and network analyzer for professional penetration testers. Its effectiveness is proven in the industry, and it remains the go-to choice for many when it comes to dissecting captured network packets. This multi-platform tool has a cult following due to its illustrious history and has motivated the development of many modern-day sniffers like Wireshark. If you are an open-source developer interested in the field of network study, you can learn a lot using this tool.

Features of Tcpdump

• Tcpdump is a command-line tool that can be easily scripted using Linux shell scripting and other programming languages.
• Users can import pre-stored packets and display them in several formats, including HEX and ASCII, among others.
• There are many highly regarded documentation available for this packet sniffer, including entire books and Linux manuals.
• You can see the source code for a closer inspection of how Tcpdump works and may even contribute to its development.

Download Tcpdump

20. SQLMap

SQLMap is an excellent open-source tool that allows admins to search for SQL injection vulnerabilities in their websites and applications. This free but powerful application provides a robust testing engine that can find several types of SQL vulnerabilities, including time-based, error-based, and boolean-based blinds, among others.

Admins can easily dump tables to perform close inspections of data. Additionally, the freely available codebase of this Linux vulnerability scanner makes sure third-party developers can add extra functionalities if they want.

Features of SQLMap

• SQLMap supports almost every major DBMSs including, MySQL, Oracle Database, MsSQL, Firebird, MariaDB, IRIS, and IBM DB2.
• It is a command-line tool with support for automatic password recognition, standard authentication, and dictionary attacks.
• SQLMap can be used to escalate database privileges via connecting to the Meterpreter payload of the Metasploit framework.
• This open-source application offers excellent documentation in the form of manuals, videos, and robust issue tracking tools.

Download SQLMap

21. Zeek

Zeek is a compelling network analysis framework that has been around for a long time. This intrusion detection mechanism was originally known as Bro. It is one of the best open source security tools for exploring anomalies in personal or enterprise networks. Zeek works by capturing logs of all network activities instead of relying on signatures like many traditional IDS tools. Security testers can analyze this data by manually reviewing them or through a Security and Information Event Management (SIEM) system.

Features of Zeek

• Zeek is suitable for testing large-scale enterprise infrastructures due to its flexible and highly adaptable feature set.
• It offers an in-depth insight into the network under observation using high-level semantic analysis techniques.
• A large number of pre-built add-ons make it easy to add extra functionalities to this network analysis software.
• Zeek offers multiple builds for enterprises and developers, including an LTS release, feature release, and a dev version.

Download Zeek

22. Kali Linux

Many people agree that Kali Linux is arguably one of the best open source security testing tools for professionals. It is a Debian-based Linux distribution that comes with all the essential tools required in modern penetration testing. This is why a lot of malicious hackers use Kali as their base system. No matter whether you’re a certified professional or a starting security enthusiast, mastery over Kali Linux will help you explore uncharted territories quite easily.

Features of Kali Linux

• Kali Linux is available on a wide range of platforms, including ARM-based systems and the VMware virtual machine.
• Users can create live installations based on personal preferences and use several encryption mechanisms for protection.
• It allows testers to build custom penetration testing environments by choosing from a large collection of Metapackages.
• You can even run Kali on Android-based smartphones using the Linux Deploy application and chroot the environment if you want.

Download Kali Linux

23. GRR – Google Rapid Response

GRR or Google Rapid Response is a compelling incident response framework developed by Google for maintaining live forensic analysis jobs from a remote environment. It consists of a server and client written in Python. The client or agent portion is deployed on the target systems, and they are managed through the server. It is a fully open-source project so you can add custom features based on personal requirements very easily.

Features of GRR

• Google Rapid Response is entirely cross-platform and runs smoothly on Linux, FreeBSD, OS X, and Windows systems.
• It utilizes the YARA library for analyzing remote memory and provides access to OS-level details and the filesystem.
• Admins can effectively monitor remote clients for CPU usage, memory details, I/O usage, and many more.
• GRR is fully equipped for handling modern security incidents and allows automatic infrastructure management.

Download GRR

24. Grabber

Grabber is a lightweight and portable Linux vulnerability scanner for websites, forums, and applications. It is one of the most useful open source security testing tools for assessing personal web apps. Since Grabber is extremely lightweight, it doesn’t offer any GUI interface.

However, controlling the application is quite straightforward, and even beginners can test their applications using it. Overall, it is a pretty decent choice for starting security enthusiasts and app developers who’re looking for portable testing tools.

Features of Grabber

• Grabber can be used for simple AJAX verifications, cross-site scripting, and SQL injection attacks.
• This open source testing tool is written using Python and is very easy to extend or customize.
• You can use Grabber to check logical flaws in JavaScript-based applications very easily.
• Grabber creates a simple but useful stats analysis file highlighting its findings and major details.

Download Grabber

25. Arachni

Arachni is a feature-rich, modular web application testing framework written in Ruby. Security professionals can use it to perform a wide range of tasks. It is quite simple to use but does not lack in power itself. Moreover, the modular nature of this tool allows users to integrate it easily with other open source security testing tools like Metasploit. Since the source code of this software is free to access and modify, third-part devs can add newer functionalities without any restrictions.

Features of Arachni

• Arachni comes with a nice and intuitive graphical user interface, which makes it very easy to manage.
• It exposes a robust set of REST APIs that makes integration easier for open source developers.
• Arachni offers multiple deployment options, including distributed platforms and personal servers.
• It can be used for checking cross-site scripting, SQL injections, code injections, and file inclusion variants.

Download Arachni

Ending Thoughts

As we continue to rely on software, security has become more important than ever. Thankfully, a large number of open source security tools make it easy for professionals to inspect vulnerabilities and allow developers to patch them before someone exploits them. Our editors have outlined some of the most widely used testing tools for our users in this guide.

No matter whether you’re a professional tester or a mere enthusiast, having a knowledge of these tools will help you mitigate many security flaws in the future. Hopefully, this guide provided you the essentials you were looking for. Let us know your thoughts in the comment section below.