April 28th I've found a endpoint in a thirth party module Klaviyo Magento 2 which allows to read private customer data from stores. It works by reclaiming any guest-cart as your own and reading the private data for the orders in the Magento API.
- Date: April 28 2021
- Who: Jeroen Boersma
- Target: Klaviyo Magento 2 module
- Version: 1.0.0 and up - 2.1.0
- Fixed in: 3.0.0 (May 25 2021)