Setracker2 Children's Smartwatch Ecosystem Generation of Predictable Numbers or Identifiers

Setracker2 Android Companion App com.tgelec.setracker versions 3.1.5 and prior have a predictable registration ID derived from IMEI. The enrollment system lacks additional authentication before assignment. If an attacker is able to obtain the registration ID, they would be able to arbitrarily enroll watches belonging to other users.