MongoDB - Extracting data (admin password) using NoSQL Injection - MMACTF 2016 Web 100 writeup
https://blog.0daylabs.com/2016/09/05/mongo-db-password-extraction-mmactf-100/

Original writeup (https://blog.0daylabs.com/2016/09/05/mongo-db-password-extraction-mmactf-100/).