Script to import XML or JSON data and convert to CSV file

General information for the business: private project
Kind of development: New program from scratch
Num. of modules: 1
Description of every module: A script is needed to download zipped data file and convert to csv.

Choice of script language is up to developer.

Script must run on linux using command line.

Script must be capable of running as a cron job.

Note: Largest file unzipped is approx 100mb.

Output should be a csv file, first line in the csv should be column headers.
Description of requirements/functionality: Developer to choose which data file is best for their script (xml or json).

Files to convert is located here; https://nvd.nist.gov/vuln/data-feeds

Two files attached, they are the same data, one is xml and other is json. please review them.

For info only: the intention is to use csv files to import into mysql at later date. i do not require any mysql or php related import scripts.

I do not require any changes to the existing website, no UI work etc.
CMS and Admin requirements: none. developer must create and test script on their own linux servers/workstations.
OS requirements: Linux
Extra notes: