An issue was discovered in the "Email Subscribers & Newsletters" plugin before 3.4.8 for WordPress. Sending an HTTP POST request to a URI with /?es=export at the end, and adding option=view_all_subscribers in the body, allows downloading of a CSV data file with all subscriber data.
- https://www.exploit-db.com/exploits/43872/
- https://github.com/20142995/nuclei-templates