Linking Website Accounts to Progress/Values in WebGL Game

This is simultaneously a Unity3D and web development question. Similar to how Blizzard connects accounts used in forums to their character and shows their statistics/information, I am trying to set up a system where a user account is connected to an account in an online browser-based game. I would like to save statistics and be able to view them through the website.

I am also willing to change and use what ever CMS works the best for communicating back and forth with Unity