How to Prove to Auditors that You've Remediated CVEs in Kubernetes

Today, the cybersecurity landscape is changing quickly with the increase of AI capabilities used by attackers and defenders alike. In this environment, effectively managing and remediating Common Vulnerabilities and Exposures (CVEs) remains important for maintaining a secure Kubernetes environment. However, it's not enough to simply address these vulnerabilities; you must also be able to demonstrate to auditors that you've taken the appropriate action after public disclosure of such vulnerabilities. So, how can you prove CVE remediation to auditors, particularly in Kubernetes environments, which are famously complex and ephemeral in nature?

Why Remediate CVEs?

Before diving into how to prove that you’ve remediated CVEs, it's probably a good idea to clarify why CVE remediation is important:

1. Security: Addressing vulnerabilities reduces the risk of a malicious actor exploiting a CVE to carry out exploits and breaches.
2. Compliance: Many regulatory frameworks require timely remediation of known vulnerabilities.
3. Trust: Demonstrating effective vulnerability management builds confidence with partners, clients, and customers. A significant breach can damage your reputation and put your business at risk.

Establishing a Robust CVE Management Process

To effectively prove CVE remediation to auditors, you need a comprehensive vulnerability management process in place, which includes these four basic components:

1. Continuous Vulnerability Scanning

Implement automated vulnerability scanning tools that regularly check your Kubernetes clusters, container images, and associated components for known CVEs. This ongoing process ensures you're always aware of potential vulnerabilities as they emerge.

2. Prioritization & Risk Assessment

Not all CVEs pose the same level of risk, and while some are consistently a concern for everyone, there are other factors to consider based on your business and infrastructure. Develop a process internally to prioritize vulnerabilities based on factors such as:

• CVSS (Common Vulnerability Scoring System) score. This reflects the technical severity of the vulnerability based on attack vector; attack complexity; privileges required; user interaction; and the confidentiality, availability, and integrity of your data and systems.
• Real-world impact. Even if the CVSS score is high, the impact can vary based on affected systems (such as whether it’s in a widely used piece of software), whether it exposes sensitive data, and whether exploiting the vulnerability will disrupt critical business operations.
• Exploitability in your context. Is there a proof-of-concept (POC) available—a working exploit that’s publicly available? Is it actively being exploited in the wild? How easy is it for a malicious actor to exploit the vulnerability, with or without a POC?
• Context. A vulnerability in a system that’s not critical to your operations may pose less risk than a vulnerability in a critical system. Also consider whether you have compensating controls (such as firewalls and intrusion detection systems) that impact the risk posed by the CVE.
• Remediation options. Is there a patch available to fix the vulnerability? Plus, how easy is it to apply the patch? Sometimes patches require downtime or more extensive effort, pushing you to find alternative mitigation strategies.

3. Remediation Planning and Execution

Once a CVE has been disclosed and identified in your environments, make a plan for how to address them. Each plan will likely include these steps:

• Document the details of the vulnerability (CVE identifier, vulnerability name and description, CVSS score, affected software or system (including version), and vulnerability type (for example, buffer overflow, SQL injection, cross-site scripting).
• Develop a remediation plan with clear steps and timelines, including whether a patch is available, where to get the patch, and how to apply it. It also includes documenting any temporary workarounds or mitigation strategies that you can use if a patch is not yet available. Also note relevant information from the software vendor, including security advisories and bug reports.
• Assign responsibility to specific team members, so you know who is responsible for what.
• Execute the remediation actions (patching, configuration changes, upgrades).

4. Verification and Testing

After remediating a vulnerability, test your patch or workarounds! Make sure the vulnerability has been addressed successfully, that the fix hasn't introduced new issues or regressions, and that system functionality remains intact. A fixed CVE in a non-functional system isn’t going to do your business much good.

Kubernetes-Specific Tools and Practices

For Kubernetes environments, use the following approaches to improve your CVE remediation process and make it easy to demonstrate to auditors.

1. Image Scanning and Registry Management

Implement container image scanning as part of your CI/CD pipeline, a secure container registry, and an admission controller that limits which repos can be used for images in the cluster. This allows you to catch vulnerabilities before they reach your clusters and provides an audit trail of image versions and their security status.

2. Kubernetes Version Control

Maintain a clear record of Kubernetes version upgrades, including:

• Dates of updates for Kubernetes versions, addons, APIs, and deployments
• Version changes (from and to) and dates of the change.
• Specific CVEs addressed by any updates, and review release notes.

3. Automated Policy Enforcement

Use tools such as Fairwinds’ open source Polaris policy engine or Open Policy Agent (more commonly referred to as OPA) to enforce security policies and prevent the deployment of vulnerable or non-compliant applications. Document these policies and their enforcement mechanisms for auditors.

Documenting Remediation for Auditors

Proper documentation is key to proving CVE remediation to auditors. Make sure you have documented policies and procedures for vulnerability management. Maintain detailed records, which should include:

• Date and time the CVE was discovered
• Scanning tool or method used
• Affected components and their versions
• CVSS score and vector
• Potential impact analysis
• Prioritization decision and justification
• Detailed steps taken to address the vulnerability (including workarounds and compensating controls)
• Patches or updates applied (including version numbers)
• Configuration changes made
• Test cases and methodologies used
• Results of post-remediation scans
• Before and after comparisons demonstrating the fix
• Team members involved in the remediation process
• Management approvals for high-risk or critical vulnerabilities

Presenting Evidence to Auditors

When it's time to demonstrate your CVE remediation efforts to auditors, you’ll need to provide a clear timeline of the vulnerability lifecycle, from discovery to remediation and verification. You’ll need to generate comprehensive reports from your vulnerability management tools, showing initial vulnerability scans, remediation actions taken, and post-remediation scans confirming the fix.

You’ll also need to show how your ongoing vulnerability management process works, including regular scanning schedules, alert mechanisms for newly identified CVEs, and the integration with ticketing systems for tracking remediation efforts. This will also help you provide evidence of adherence to internal policies and industry best practices, including remediation SLAs based on vulnerability severity, the approval processes for critical changes, and that you conduct regular security reviews and audits.

All of this will also help you generate a trend analysis that shows how your vulnerability management has improved over time, such as a reduction in average time-to-remediation, a decrease in the number of high and critical vulnerabilities, and improvements in your organization’s overall security posture

Audit-ready CVE Remediation

Proving CVE remediation to auditors in a Kubernetes environment requires you to put robust processes, thorough documentation, and effective use of specialized tools in place. By implementing Kubernetes policy enforcement, vulnerability scanning, and maintaining detailed records of your remediation efforts, you can demonstrate your commitment to security and compliance with confidence. You’ll not only be able to pass audits, but also maintain a secure Kubernetes environment.

If you need help building or maintaining secure, compliant Kubernetes infrastructure, Fairwinds can help. Find out how.