CvssSuite

This Ruby gem helps you to process the vector of the Common Vulnerability Scoring System. Besides calculating the Base, Temporal and Environmental Score, you are able to extract the selected option.

Installation

Add this line to your application's Gemfile:

gem 'cvss-suite'

And then execute:

$ bundle

Or install it yourself as:

$ gem install cvss-suite

Usage

require 'cvss_suite'

cvss = CvssSuite.new('AV:A/AC:M/Au:S/C:P/I:P/A:P/E:POC/RL:TF/RC:UC/CDP:L/TD:M/CR:M/IR:M/AR:M')

vector = cvss.vector    # 'AV:A/AC:M/Au:S/C:P/I:P/A:P/E:POC/RL:TF/RC:UC/CDP:L/TD:M/CR:M/IR:M/AR:M'
version = cvss.version  # 2
valid = cvss.valid?     # true

# Scores
base_score = cvss.base_score                        # 4.9
temporal_score = cvss.temporal_score                # 3.6
environmental_score = cvss.environmental_score      # 3.2
overall_score = cvss.overall_score                  # 3.2

# Available options
access_vector = cvss.base.access_vector.name                # 'Access Vector'
remediation_level = cvss.temporal.remediation_level.name    # 'Remediation Level'

access_vector.choices.each do |choice|
    choice[:name]           # 'Local', 'Adjacent Network', 'Network'
    choice[:abbreviation]   # 'L', 'A', 'N'
    choice[:selected]       # false, true, false
end

# Selected options
cvss.base.access_vector.selected_choice[:name]          # Adjacent Network
cvss.temporal.remediation_level.selected_choice[:name]  # Temporary Fix

# Exceptions

cvss = CvssSuite.new('random_string')  # invalid vector
valid = cvss.valid?     # false
version = cvss.version  # will throw CvssSuite::Errors::InvalidVector: Vector is not valid!
cvss.base_score         # will throw CvssSuite::Errors::InvalidVector: Vector is not valid!

cvss = CvssSuite.new(1337)  # invalid vector
valid = cvss.valid?     # false
version = cvss.version  # will throw CvssSuite::Errors::InvalidVector: Vector is not valid!
cvss.base_score         # will throw CvssSuite::Errors::InvalidVector: Vector is not valid!

CvssSuite.new()                        # will throw a ArgumentError

cvss = CvssSuite.new('AV:N/AC:P/C:P/AV:U/RL:OF/RC:C')   # invalid vector, authentication is missing
version = cvss.version  # 2
valid = cvss.valid?     # false
cvss.base_score         # will throw CvssSuite::Errors::InvalidVector: Vector is not valid!

Notable Features

Properties (Access Vector, Remediation Level, etc) do have a position attribute, with this they can be ordered the same way they appear in the vector.

Known Issues

Currently it is not possible to leave a attribute blank instead of ND/X. If you don't have a value for a attribute, please use ND/X instead.

Because the documentation isn't clear on how to calculate the score if Modified Scope (CVSS 3.0 Environmental) is not defined, Modified Scope has to have a valid value (S/U).

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/siemens/cvss-suite. This project is intended to be a safe, welcoming space for collaboration.