What is a Zero Trust testing?

The Zero Trust model is built upon the following core principles based on NIST 800-207:

1. Resource definition
   All data sources and computing services are considered resources, requiring clear identification and categorization.
2. Secure communication
   All information is secured, regardless of network location or device type.
3. Strong device identity
   Access to individual enterprise resources is granted on a per-session basis, ensuring that devices are authenticated and authorized before access is granted.
4. Dynamic authentication
   Access to resources is determined by dynamic policies that consider factors such as user identity, application/service, device characteristics, and behavioral attributes.
5. Continuous monitoring
   The company monitors and measures the integrity and security posture of all owned and associated assets to detect and mitigate threats.
6. Strict enforcement
   Authentication and authorization are strictly enforced before access is allowed, ensuring that only authorized users can access specific resources.
7. Risk-based policies
   Policies are set based on the value of the service or data, prioritizing protection of critical assets.
   

Zero Trust testing is a critical component of validating the effectiveness of a Zero Trust security framework. Here's a step-by-step guide on how to conduct it:

• Identify critical assets, sensitive data, applications, and network infrastructure.
• Document current access control policies, network segmentation, user roles, and permissions.
• Establish a baseline of normal user behavior for monitoring purposes.

• Develop or review policies aligned with the "least privilege" principle.
• Implement multi-factor authentication (MFA), just-in-time access, and role-based access control (RBAC).

• MFA Testing: Attempt to bypass MFA systems and identity management controls.
• Verify that users have only the necessary access.
• Test vulnerability to identity theft and unauthorized access.
• Ensure timely updates to access permissions based on role changes.

• Perform tests to determine if network segmentation prevents lateral movement of attackers within the network. For instance, simulate compromised user credentials and see if the attacker can move across network segments.
• Ensure segmentation and firewall rules are applied correctly, limiting communications between network segments.
• Verify that all internal and external communications are encrypted.

• Verify application-level access controls.
• Ensure data is encrypted in transit and at rest.
• Simulate attacks. Conduct penetration tests to simulate attacks targeting applications, including SQL injection, Cross-Site Scripting (XSS), and other common vulnerabilities.

• Verify devices meet security requirements (e.g., patching, endpoint protection).
• Test endpoint protection mechanisms.
• Test the impact of compromised devices. Ensure that compromised devices are automatically quarantined or blocked from the network.

• Ensure data is encrypted at all times.
• Test DLP mechanisms to prevent unauthorized data transfer.
• Verify access controls for sensitive data.

• Evaluate SIEM tools for real-time monitoring and detection.
• Test the system's ability to detect anomalous user behavior.
• Verify that alerts trigger appropriate actions.

• A red team simulates advanced persistent threats (APTs), insider attacks, and external breaches to evaluate how well Zero Trust defenses hold up in a real-world scenario.
• Use penetration testing tools to simulate attackers trying to bypass the Zero Trust controls.
• Evaluate how well your incident response team reacts to a breach or anomaly detection.

• After testing, analyze what vulnerabilities or weaknesses were uncovered.
• Modify access policies, configurations, or security tools based on findings to enhance the Zero Trust implementation.
• Regularly review and test the architecture as the zero test environment evolves (new applications, users, or changes to the network).