Moodle does not consider "don't send" attributes during hub registration
Moodle through 2.1.10, 2.2.x before 2.2.10, 2.3.x before 2.3.7, and 2.4.x before 2.4.4 does not consider "don't send" attributes during hub registration, which allows remote hubs to obtain sensitive site information by reading form data.