Compare 10+ Open Source Security Audit Tools in 2025

Previously, I explained 30+ security audit tools based on their specializations. To compare vulnerability scanning, web application scanning, and security automation & simulation capabilities of the best free open-source auditing tools, I spent several hours going through the documentation and watching demos of these tools. Here are my key takeaways:

The context of open-source security auditing tools can vary. At its core, these tools involve popular vulnerability scanners, penetration testers (e.g., Nmap, OWASP ZAP), and other niche tools focusing on Active Directory auditing (e.g., AD Miner).

See vendor selection criteria.

Host-based auditing tools can:

• Access system files (e.g., /etc/ssh/sshd_config).
• Detect vulnerabilities in closed ports and non-exposed services.

Even run locally, network-based auditing tools cannot:

• Access system config files (e.g., /etc/ssh/sshd_config)
• Detect non-exposed services or closed ports

Vulnerability scanning capabilities 

• CVE scanning: Identifying systems affected by known vulnerabilities cataloged in the Common Vulnerabilities and Exposures (CVE) database.
• OS-level flaw detection: Assessing local system configurations, permissions, and misconfigurations that may lead to compromise.

Web application scanning capabilities

Tools that cannot detect the following vulnerabilities (e.g., SQL injection) can still observe these vulnerabilities in network traffic if:

• The attack is performed over an unencrypted protocol (like HTTP)
• You are capturing traffic at the right point (e.g., between the attacker and the vulnerable server)

Vulnerability descriptions:

• SQL Injection (SQLi): An attack where malicious SQL code is injected into input fields, allowing attackers to manipulate or access a database.
• Cross-Site Scripting (XSS): An attack where malicious scripts are injected into web pages, which are executed in the victim’s browser, often stealing sensitive information.
• Cross-Site Request Forgery (CSRF): An attack that tricks users into performing unintended actions on a website where they are authenticated, using their credentials without consent.

Security automation and simulation capabilities

Some open-source auditing tools can focus on translating these requirements into practical security processes within systems and infrastructure with:

• Automated auditing
• Real-world attack simulations
• AI editors

• Developers: To test or improve web application hardening by identifying potential security flaws in the code or deployed infrastructure.
• System administrators: To run regular health scans, uncover weaknesses, and maintain secure network environments, ensuring systems remain protected against emerging threats.
• IT auditors: To evaluate and demonstrate security gaps to colleagues or clients, providing actionable insights for security improvements and ensuring compliance with industry standards.
• Penetration testers: To assess and discover vulnerabilities in client systems, simulating attacks to identify risks that could lead to system compromise, helping businesses protect sensitive data.

What is it: Penetration testing, vulnerability scanning framework

Rapid7 Metasploit allows you to quickly test vulnerabilities and validate them with exploit attempts. This is a key benefit for deeper, hands-on assessments. It is ideal for operational teams, focusing on vulnerability management, automated scanning, and integration with ticketing systems for remediation workflows.

Additionally, the solution integrates with other tools in the Rapid7 ecosystem, such as SIEMs, which can help correlate vulnerabilities with other logs and data sources.

Nmap

What is it: Penetration tester, vulnerability scanner 

Nmap is one of the most commonly used network inventory and security assessment tools. It is used for:

• monitoring host uptime, 
• discovering devices and open ports
• running security scans

OWASP ZAP

What is it: Penetration tester, vulnerability scanner 

OWASP ZAP is well-suited for those requiring web application security and offers features like active and passive scanning, as well as automated reporting. It supports scripting and extensions, offering flexibility for specific tasks or technical use cases.

Nuclei

What is it: Penetration tester, vulnerability scanner for cloud environments

Nuclei uses a templating library to scan applications, cloud infrastructure, and networks to find and remediate vulnerabilities. You can modify and create your own Nuclei templates to tailor them for your specific target environment. It uses customizable YAML templates to scan for:

• CVEs
• Misconfigurations
• Exposed services or sensitive files
• Web application security issues

It also offers an AI-powered editor to automate vulnerability detection by converting internal data into an automated pipeline.

Nikto

What is it: Penetration tester, vulnerability scanner for web servers

Nikto is a web server vulnerability scanner that automates the process of checking for out-of-date software. Nikto scans web servers to identify potential security issues, including:

• Outdated server versions
• Unpatched vulnerabilities
• Dangerous files 

OpenVas

What is it: Penetration tester, vulnerability scanner for networks

OpenVAS generates automatic reports after scans, which can be sent by email for further analysis and remediation. While it is useful for preliminary scans and validating external test results, OpenVAS is not ideal for enterprise-level security assessments due to its limited features, unrefined user interface, and lack of regularly updated plugins. It requires a license for an appliance if you want it to check for “enterprise” vulnerabilities.

Additionally, it only supports non-credentialed scans, which may not provide as in-depth analysis as credentialed scans.

Wireshark

What is it: Network protocol analyzer, packet sniffer

Wireshark is used for network analysis/troubleshooting. It allows users to capture and examine the data traveling through a network in real-time. Key features of Wireshark:

• Packet capture
• Protocol analysis
• Real-time traffic monitoring 
• Filtering and searching
• Data export

Lynis

What is it: System configuration auditing tool

Lynis is a security tool for systems running Linux, macOS, or Unix-based operating systems.

Lynis scanning is modular and adaptive, it tests only the components it detects, such as available system tools and libraries. The benefit is that no installation of other tools is needed. Use cases for Lynis include:

• Security auditing
• Compliance testing (e.g. PCI, HIPAA, SOx)
• Penetration testing
• Vulnerability detection
• System hardening

ScoutSuite

What is it: Cloud security posture management tool

ScoutSuite scans and audits your cloud infrastructure to identify security misconfigurations, vulnerabilities, and compliance issues. It can be used offline once the data is collected. ScoutSuite supports the following cloud providers:

• Amazon Web Services
• Microsoft Azure
• Google Cloud Platform
• Alibaba Cloud (alpha)
• Oracle Cloud Infrastructure (alpha)

ADMiner

What is it: Active Directory auditing tool

AD Miner audits Active Directory environments (both on-premise and Entra ID). The tool offers a thorough overview of potential vulnerabilities via a static, web-based report. Features of the web-based reports include:

• Listings of identified vulnerabilities
• Interactive graphs for visual analysis
• Historical key indicators for tracking changes over time
• Risk ratings to prioritize threats and necessary actions

Ssh-audit

What is it: SSH server & client security auditing tool

Ssh-audit helps audit the configuration of SSH servers or clients. The tool provides two main audit options:

1. Server audit: To audit the configuration of an SSH server, you need to enter the server’s hostname or its IPv4/IPv6 address and specify the port number. After that, you select the type of audit:

• Standard audit: A basic audit of the SSH configuration.
• Policy audit: This audit checks the server against a specific security policy, such as a “Hardened Amazon Linux 2023” configuration.

2. Client audit: For auditing an SSH client configuration, you click a button to start the audit process. After that, any username can be used to connect to the server, allowing the audit to check the client’s configuration.

PowerUpSQL

What is it: SQL Server discovery, configuration auditing tool

PowerUpSQL is a PowerShell Toolkit for auditing SQL servers. It is used for:

• SQL server discovery: Quickly identifies all SQL Server instances in an AD domain, providing an overview of configurations, versions, and vulnerabilities.
• Weak configuration auditing: Checks for misconfigurations like weak authentication and insecure settings, such as weak service accounts and lack of encryption.
• Privilege escalation auditing: Helps exploit privilege escalation opportunities by abusing misconfigurations and SQL Server vulnerabilities to gain higher access levels.
• Post-exploitation: Enables OS command execution and data exfiltration from compromised SQL Servers, allowing further system manipulation and lateral movement.

InQL

What is it: Vulnerability scanner 

InQL is an open-source Burp Suite (suite of security testing tools for web application security and auditing) extension for GraphQL testing, offering vulnerability detection, customizable scans, and seamless Burp integration.

Sj

What is it: Endpoint discovery and auditing tool

Sj is a command-line tool designed to help audit exposed Swagger/OpenAPI definition files by evaluating the related API endpoints for weak authentication. It also offers command templates for manual vulnerability testing.

Vendor selection criteria

• GitHub stars: 600+
• Last update: At least one version was released in the last three months as of March 2025.