What is EPSS?

The Exploit Prediction Scoring System (EPSS) is a data-driven model designed to estimate the likelihood that a software vulnerability will be exploited in the wild within a specific time frame. EPSS is used by security professionals to prioritize vulnerabilities for remediation by focusing on those most likely to be targeted by attackers. The system uses various data points, such as historical exploit data, vulnerability characteristics, and metadata, to calculate a probability score that helps organizations manage cybersecurity risk more effectively.  The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

How does EPSS differ from CVSS?

EPSS complements the Common Vulnerability Scoring System (CVSS) by adding an additional layer of prioritization focused on exploitability. While CVSS provides a severity score based on the potential impact of a vulnerability, EPSS estimates the likelihood of that vulnerability being exploited. Together, these scores help organizations not only understand the severity of vulnerabilities but also focus their resources on those most likely to be exploited.

How can organizations use EPSS in their security operations?

Organizations can integrate EPSS into their vulnerability management processes to prioritize patches and other remediation efforts. By focusing on vulnerabilities with higher EPSS scores, security teams can reduce the likelihood of successful attacks by addressing the most imminent threats. EPSS can also be used in conjunction with other tools and frameworks, such as CVSS, to create a more comprehensive risk management strategy.