Kasa EC70 v4 and EC71 v4 do not logically disable the production debug interface at the firmware or chip level and do not lock the bootloade

Kasa EC70 v4
and EC71 v4 do not logically disable the production debug interface at the
firmware or chip level and do not lock the bootloader.  Although the debug traces are physically
severed during manufacturing, an attacker with physical access can restore the
connection, interrupt the boot process, and manipulate boot parameters to enter
a non-standard initialization path that exposes an unauthenticated root shell
during startup.

Successful exploitation may allow an
attacker with physical access to obtain root-level command access during device
startup, resulting in loss of confidentiality, integrity, and availability for
the affected device. Exploitation requires device disassembly, restoration of
the severed debug connection, and manipulation of the boot process.