The Arrival of CVSS 4.0: Enhancing the Utility of Vulnerability Scores?
The Common Vulnerability Scoring System (CVSS) has been in need of an update for some time, and in November 2023, CVSS v4.0 was officially released. This new version, designed to address the limitations of CVSS v3.1 and align with current cybersecurity trends, introduces significant changes. One key update is the inclusion of new supplemental metrics for more customizable vulnerability management.
Invicti is one of the first dynamic application security testing (DAST) solution providers to integrate CVSS 4.0 vulnerability scores into its products. This article provides an overview of CVSS 4.0 and explains how these new metrics are displayed in Invicti and Acunetix vulnerability scan results.
Understanding CVSS
When dealing with security issues, having a severity score can be invaluable for prioritizing vulnerability response efforts. The CVSS scoring system is used to assess the severity of vulnerabilities, but calculating these scores can be complex due to various factors influencing vulnerability severity. Different versions of CVSS have been developed over the years, with CVSS v4.0 being the latest iteration as of 2023.
The base score in CVSS reflects the technical severity of a vulnerability on its own. However, this score may not always provide a complete understanding of the risk associated with the vulnerability. With CVSS 4.0, the goal was to enhance the scoring system by adding additional metrics to offer a more comprehensive view of each vulnerability, aiding in better risk analysis.
Key Updates in CVSSv4.0
CVSS 4.0 introduces new categorizations to provide a more detailed assessment of vulnerabilities, including threat and environmental scores in addition to the base score. By combining different component scores, organizations can obtain a more accurate assessment of the risk posed by a vulnerability. The extended CVSS-BTE score aims to provide a more precise indication of risk, comparable to proprietary risk scoring methods.
CVSS Numerical Score vs. CVSS Vector
Each CVSS score consists of a numerical value and a vector string that encodes specific metrics and values. The numerical score gives an overview of severity, while the vector provides detailed information about the vulnerability. As CVSS metrics expand, the vector string becomes longer, offering a more detailed description of the vulnerability.
For example, CVE-2014-0160 (Heartbleed vulnerability) would be described differently in CVSS 4.0 compared to 3.1, showcasing the increased detail provided by the new version.
Enhanced Base Metrics
CVSS 4.0 introduces changes to the base metrics, such as removing the SCOPE metric and redefining Attack Complexity and User Interaction metrics for better accuracy. Additionally, a new supplemental metric group has been added to allow organizations to define vulnerability attributes in context. These optional metrics can provide additional information for a more thorough risk assessment.
Support for CVSSv4.0 in Invicti and Acunetix
Invicti is at the forefront of implementing CVSS 4.0 support in its DAST products, enabling users to access the new scoring system for vulnerability assessment. The inclusion of CVSS 4.0 scores in vulnerability reports enhances the risk management capabilities of Invicti and Acunetix users, offering multiple options for vulnerability mitigation.
CVSS 4.0 support is now available in all Invicti and Acunetix products, with updates for specific on-premises versions scheduled for January 2024.
Conclusion
The enhancements in CVSS 4.0 aim to address the limitations of previous versions and provide a more comprehensive vulnerability scoring system. While the increased complexity of the system may pose challenges, the granular approach offered by CVSS 4.0 promises a more realistic assessment of vulnerabilities. Organizations that effectively leverage the new scoring system can benefit from standardized risk calculations and more accurate vulnerability reports.
As the industry adapts to CVSS 4.0, the standard is set to improve the accuracy and relevance of vulnerability scoring, benefiting vulnerability databases and information providers alike. While some critiques suggest fundamental flaws in centralized scoring systems, CVSS 4.0 represents a step forward in providing detailed and informative vulnerability scores.
For more details on CVSS 4.0, refer to the official specification document available on the first.org website.
