CVSS scores

The Common Vulnerability Scoring System (CVSS) score shows the overall security impact of a vulnerability. AppScan Enterprise calculates the score based on available information for one or more metrics. The more information available, the more precise the score becomes.

AppScan Enterprise calculates and displays scores for both CVSS 3.1 and CVSS 4.0:

  • CVSS 3.1: Uses a combined approach of Base and Temporal metrics at the issue level and Environmental metrics at the application level.

  • CVSS 4.0: Calculates the score based on Base attributes but doesn't include Environmental metrics. Modifying the environmental attributes of an application impacts only the CVSS 3.1 calculation.

Attribute mapping and constraints

AppScan Enterprise maps metric values to the attributes of an issue (security vulnerability) or the application where the issue was found.
Note:
You can't delete or modify these attributes in AppScan Enterprise, but you can change their values.

CVSS 4.0 implementation

AppScan Enterprise calculates CVSS 4.0 scores alongside CVSS 3.1. When you modify CVSS attributes for an issue, AppScan Enterprise recalculates both versions. New attributes are available to store the CVSS 4.0 score and CVSS 4.0 vector string.

Table 1. CVSS metrics

Metrics group Metrics name Issue or Application attribute Definition required to calculate the CVSS score
Base Attack Vector Issue Yes
Attack Complexity Issue Yes
Privileges Required Issue Yes
User Interaction Issue Yes
Scope Issue Yes
Confidentiality Impact Issue Yes
Integrity Impact Issue Yes
Availability Impact Issue Yes
Temporal Exploit Code Maturity Issue No*
Remediation Level Issue No*
Report Confidence Issue No*
Environmental

These metrics also contribute to the overall severity rating of the application.

Modified Base Metrics Application No*
Availability Requirement Application No*
Confidentiality Requirement Application No*
Integrity Requirement Application No*
Note:
  • * While it is not a requirement that these attributes be defined, the CVSS score is more focused when more metrics are defined to describe the issue.
  • Any optional attribute that is not defined is not included in the CVSS score calculation.
  • The CVSS score cannot be calculated if any required attribute is not defined. In this case, the issue severity is categorized as Undetermined.
  • For more information on the details of the CVSS metrics, refer the following links: