Use of a deterministic credential generation algorithm in /ftl/bin/calc_f2 in Small Cell Sercomm SCE4255W (FreedomFi Englewood) firmware before DG3934v3@2308041842 allows remote attackers to derive valid administrative/root credentials from the device's MAC address, enabling authentication bypass and full device access.
https://neroteam.com/blog/freedomfi-sercomm-sce4255w-englewood