Pi-hole before 6 allows unauthenticated admin/api.php?setTempUnit= calls to change the temperature units of the web dashboard. NOTE: the supplier reportedly does "not consider the bug a security issue" but the specific motivation for letting arbitrary persons change the value (Celsius, Fahrenheit, or Kelvin), seen by the device owner, is unclear.
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.