Certipy-AD on Kali Linux Tools

Introduction

In the world of cybersecurity and penetration testing, attacking Active Directory (AD) environments is a key focus for ethical hackers and security professionals. Microsoft Active Directory is widely used by organizations to manage users, computers, and resources, making it a prime target for adversaries. Kali Linux, a premier penetration testing distribution, offers a variety of tools for assessing AD security. Among these tools, Certipy-AD has emerged as a crucial utility for exploiting AD Certificate Services.

This blog post will explore Certipy-AD, its functionalities, installation, and how to use it effectively in penetration testing scenarios on Kali Linux.

What is Certipy-AD?

Certipy-AD is a powerful Python-based tool designed to assess and exploit vulnerabilities in Active Directory Certificate Services (ADCS). It is particularly useful for detecting and exploiting misconfigurations related to certificate-based authentication in Active Directory environments. This tool enables attackers and security professionals to:

• Enumerate AD CS configurations
• Exploit privilege escalation vectors
• Perform account takeovers using certificate-based authentication
• Retrieve and abuse user and machine certificates

Understanding ADCS and its security implications is crucial for red teamers, penetration testers, and blue team defenders alike.

Installing Certipy-AD on Kali Linux

Certipy-AD is not pre-installed in Kali Linux by default. However, installing it is straightforward and requires Python3 and Pip.

Prerequisites

Before installing Certipy-AD, ensure that you have the necessary dependencies installed on your Kali Linux machine:

sudo apt update && sudo apt upgrade -y
sudo apt install python3 python3-pip

Installation Steps

You can install Certipy-AD using Pip as follows:

pip3 install certipy-ad

Once installed, verify the installation by running:

certipy -h

This command should display the available options and usage instructions.

Using Certipy-AD for Active Directory Attacks

Certipy-AD provides multiple attack vectors for exploiting Active Directory Certificate Services. Below are some common use cases:

1. Enumerating ADCS Configurations

One of the first steps in attacking ADCS is enumeration. Certipy-AD allows users to gather information about CA servers, certificate templates, and potential misconfigurations.

Run the following command to enumerate ADCS configurations:

certipy find -u 'DOMAIN\Username' -p 'Password' -dc-ip <DomainControllerIP>

This will retrieve details about the CA servers, templates, and security settings.

2. Requesting a Certificate

If you identify a vulnerable certificate template, you can request a certificate using Certipy:

certipy req -u 'DOMAIN\Username' -p 'Password' -dc-ip <DomainControllerIP> -ca 'CAName' -template 'VulnerableTemplate'

This command requests a certificate using the specified template and CA. If the template is vulnerable, it may allow authentication or privilege escalation.

3. Using a Certificate for Authentication

After obtaining a certificate, you can use it to authenticate as the targeted user and potentially escalate privileges.

Convert the certificate to a format usable by Rubeus or Mimikatz:

certipy auth -pfx certificate.pfx -dc-ip <DomainControllerIP>

This enables authentication without requiring a password, potentially leading to further attacks.

4. Exploiting ESC1 and ESC2 Attacks

ADCS misconfigurations are classified into different ESC (Enterprise Security Certificate) scenarios, such as ESC1 and ESC2.

• ESC1 Attack: A user with enrollment rights can request a certificate for a higher-privileged account.
• ESC2 Attack: Exploiting misconfigured certificate templates to obtain high-privilege access.

To exploit an ESC1 vulnerability:

certipy req -u 'LowPrivUser' -p 'Password' -dc-ip <DomainControllerIP> -ca 'CAName' -template 'ESC1Template'

Using the obtained certificate, authenticate as a high-privileged user and escalate access.

Defensive Measures and Mitigations

While Certipy-AD is an excellent offensive tool, defenders must take precautions to secure ADCS. Here are some key mitigation strategies:

1. Limit Certificate Enrollment Permissions: Restrict who can request certificates to prevent unauthorized access.
2. Monitor Certificate Requests: Implement logging and alerting for certificate-related activities.
3. Disable Unused Certificate Templates: Remove or restrict insecure templates.
4. Use Strong Authentication Methods: Avoid weak authentication mechanisms and enforce multi-factor authentication (MFA).
5. Regular Security Audits: Perform regular security assessments to identify and remediate misconfigurations.

Conclusion

Certipy-AD is a powerful tool that enhances the ability of penetration testers and red teamers to identify and exploit weaknesses in Active Directory Certificate Services. However, organizations can significantly improve their security posture by understanding how these attacks work and implementing appropriate defensive measures.

By leveraging Certipy-AD on Kali Linux, ethical hackers can simulate real-world attacks and help organizations strengthen their defenses against certificate-based threats.

For security professionals, continuous learning and proactive security assessments are key to staying ahead of attackers. Explore Certipy-AD, test responsibly, and contribute to a more secure cyber environment.

Additional Resources

• Certipy-AD GitHub Repository
• Active Directory Certificate Services Overview
• MITRE ATT&CK - ADCS Attacks

By staying informed and proactive, both red teams and blue teams can enhance their approach to Active Directory security. If you have any experiences or insights related to Certipy-AD, feel free to share them in the comments below!