Using EPSS for Effective Vulnerability Management Using Wazuh

3 min readJul 2, 2024

Introduction

In the world of cybersecurity, managing vulnerabilities is a critical task. With the sheer number of vulnerabilities that can be detected in an environment, it can be overwhelming to determine which ones to address first. Traditional methods, like relying solely on CVE scores, often fall short in helping prioritize the most imminent threats. This is where the Exploit Prediction Scoring System (EPSS) comes into play. In this post, we will explore how integrating EPSS with detected vulnerabilities can enhance your vulnerability management strategy, using tools like the Wazuh agent and Copilot.

Understanding CVE and EPSS

What are CVE Scores?

Common Vulnerabilities and Exposures (CVE) scores are standardized identifiers for vulnerabilities. They provide information on the severity of a vulnerability based on factors such as how easy it is to exploit and its impact on confidentiality, integrity, and availability. However, CVE scores don’t always indicate which vulnerabilities should be prioritized for fixing.

Introducing EPSS

The Exploit Prediction Scoring System (EPSS) is a model designed to predict the likelihood of a vulnerability being exploited within the next 30 days. Unlike CVE scores, which focus on the severity, EPSS scores help in prioritizing vulnerabilities based on their potential for exploitation, which is crucial for effective vulnerability management.

Integrating EPSS with Vulnerability Management

The Need for Prioritization

Given the vast number of vulnerabilities, it’s essential to have a method for prioritizing which ones to address first. High CVE scores don’t always mean immediate risk, and this is where EPSS scores become valuable. EPSS focuses on the likelihood of exploitation, helping you tackle the most pressing threats.

Practical Implementation with Wazuh Agent and Copilot

In the video, we see a demonstration of integrating EPSS within the Copilot tool using the Wazuh agent for vulnerability detection. Here’s how it works: 1. Detect Vulnerabilities: The Wazuh agent identifies vulnerabilities and assigns CVE scores.

2. Fetch EPSS Scores: Copilot fetches the EPSS scores for these CVEs, providing an additional layer of information.

3. Analyze Results: EPSS scores, expressed as a numerical value between 0 and 1, indicate the probability of exploitation. For example, a score of 0.91 suggests a high likelihood of exploitation.

Case Study: Prioritizing Vulnerabilities

Example 1: A vulnerability with a CVE score of 8.0 but an EPSS score of 0.91 should be prioritized over one with a CVE score of 9.0 but an EPSS score of 0.4. The former has a higher risk of being exploited soon.

Example 2: PHP vulnerabilities on a host showed high EPSS scores, indicating a critical need for patching, unlike lower-scoring vulnerabilities like FreeRDP, which can be addressed later.

Conclusion

Integrating EPSS into your vulnerability management workflow can significantly enhance your ability to prioritize and mitigate risks effectively. By focusing on the likelihood of exploitation, EPSS helps ensure that the most critical vulnerabilities are addressed first, making your cybersecurity efforts more efficient and impactful. Remember, effective vulnerability management is not just about addressing every vulnerability but prioritizing the ones that pose the most immediate threat to your environment. Tools like Copilot, combined with EPSS and Wazuh agent, provide a comprehensive approach to achieve this goal. Stay secure, and until next time, keep defending!

🚀See more details about integrating EPSS with Graylog here: SOCFortress Integrations — Vulnerability Management using the Exploit Prediction Scoring System (EPSS) | by SOCFortress | Medium

Need Help?

The functionality discussed in this post, and so much more, are available via the SOCFortress platform. Let SOCFortress help you and your team keep your infrastructure secure.

Website: https://www.socfortress.co/