Crowbar

Crowbar is an open-source brute force tool used by penetration testers to crack remote authentication services. Developed with versatility in mind, it supports a variety of authentication protocols and services, including SSH keys, RDP (Remote Desktop Protocol), VNC (Virtual Network Computing), and OpenVPN. Designed specifically to target these services through brute force password attacks, Crowbar is an essential tool in the toolkit of penetration testers who need to identify vulnerabilities in networks and applications.

Key Features

Crowbar comes with a set of key features that make it a valuable tool for penetration testers:

What Does It Do?

Crowbar is primarily used to perform brute force attacks on services that rely on user authentication. It simplifies the process of testing the strength of passwords and identifying weak points in security, particularly for services like SSH, RDP, VNC, and OpenVPN. For example, when an organization wants to evaluate the robustness of its remote access solutions, Crowbar can be used to simulate an attacker trying to gain unauthorized access through weak or easily guessable credentials.

It can also be used for password spraying attacks, where a single password is tested across multiple accounts, which helps to avoid detection by intrusion detection systems (IDS). This capability makes it a flexible tool in various scenarios, especially for testing compliance with security best practices.

What is Unique About Crowbar?

What makes Crowbar stand out from other brute force tools is its ability to perform brute force attacks on not just password-based logins but also SSH key authentication. This is a relatively unique feature among similar tools, as many brute-force applications focus solely on password guessing. Its support for a range of protocols like RDP, VNC, and OpenVPN further increases its flexibility, allowing security professionals to target a wide variety of services with a single tool.

In addition, Crowbar’s lightweight and scriptable nature make it suitable for use in automated testing frameworks, making it highly scalable for both small and large testing environments. Being an open-source project, Crowbar also benefits from community updates, which ensures that the tool evolves to address new vulnerabilities and threats.

Who Should Use Crowbar?

Crowbar is designed for penetration testers, security professionals, and system administrators responsible for evaluating the security of remote authentication services. It is particularly useful for:

Supported Platforms to Deploy Crowbar

Crowbar is primarily supported on Linux-based operating systems. It can be deployed and run on any major Linux distribution, including:

Since penetration testing often occurs in Linux environments, Crowbar's compatibility with these distributions ensures it fits into the workflows of most security professionals. Additionally, it can be easily integrated into automated testing pipelines through scripts.

Pricing

Crowbar is a free and open-source tool. Being open-source means it’s freely available for download and use by anyone. There are no premium or enterprise versions; the full feature set is accessible without cost, making it an excellent tool for both independent security researchers and larger penetration testing teams.

The development and updates are community-driven, with no associated fees, although users are encouraged to contribute to the project to support its ongoing improvement.

Short Summary

Crowbar is a powerful and versatile brute-force tool designed for penetration testers and security professionals. With its support for a range of authentication protocols, including SSH, RDP, VNC, and OpenVPN, Crowbar excels at cracking passwords and testing the strength of remote authentication services. Its open-source nature, ease of integration into automated workflows, and support for SSH key-based brute force attacks make it unique among similar tools. Whether for individual use or large-scale security assessments, Crowbar provides an essential toolset for evaluating and improving system security.