The {metæffekt} CVSS Calculator supports all versions of the CVSS standard by FIRST to model CVSS vectors and calculate their scores. It consists of the following components:

Installation

This project implements the following versions of the CVSS standard by FIRST:

• CVSS:2.0 - https://www.first.org/cvss/v2/guide
• CVSS:3.0 - https://www.first.org/cvss/v3.0/specification-document
• CVSS:3.1 - https://www.first.org/cvss/v3.1/specification-document
• CVSS:4.0 - https://www.first.org/cvss/v4.0/specification-document

Available on NPM as ae-cvss-calculator and installable via:

npm install ae-cvss-calculator

Usage

The CVSS versions are implemented in the following classes:

• Cvss2.ts
• Cvss3P0.ts
• Cvss3P1.ts
• Cvss4P0.ts

A couple of examples, using the methods that can construct and modify vectors and calculate the several different CVSS scores:

Usage V4.0

const cvss4 = new Cvss4P0()
cvss4.applyVector('CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L')
cvss4.applyVector('SC:L/SI:L/SA:L')
console.log(cvss4.toString())

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L

const cvss4 = new Cvss4P0('CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L')
cvss4.applyComponentString('MAC', 'L')
cvss4.applyComponent(Cvss4P0Components.AC, Cvss4P0Components.AC_VALUES.H) // alternatively via types
const scores = cvss4.calculateScores()
console.log(scores)

{
  "overall": 5.3,
  "vector": "CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/MAV:X/MAC:L/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X"
}

Usage V3.1

const cvss3 = new Cvss3P1('CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L')
cvss3.applyComponentString("AC", "L")
console.log(cvss3.calculateScores(false))
console.log(cvss3.calculateScores(true)) // normalize all scores to a scale 0-10 (CVSS:3.1 Exploitability, Impact)

{
  "base": 7.3,
  "impact": 3.4,
  "exploitability": 3.9,
  "temporal": null,
  "environmental": null,
  "modifiedImpact": null,
  "overall": 7.3,
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
}

{
  "base": 7.3,
  "impact": 5.7,
  "exploitability": 10,
  "temporal": null,
  "environmental": null,
  "modifiedImpact": null,
  "overall": 7.3,
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
}

Build

git clone https://github.com/org-metaeffekt/metaeffekt-universal-cvss-calculator
cd metaeffekt-universal-cvss-calculator/ae-cvss-calculator
npm install
npm run build

The minified ae-cvss-calculator.js can be found in the dist directory.

Otherwise, you can also build the packaged version by running

npm run pack