Please fork this repo and send a pull request with your changes.
A custom fact for CVE-2014-1234 should be in lib/facter/cve_2014_1234.rb with fact name cve_2014_1234 and should be a non-structured fact that returns either vulnerable or not_vulnerable.
Please include a link to cve.mitre.org to the specific CVE and any common name such as 'shellshock'.