NK? That would be crazy, those nutters have radars quite capable of discovering jetliners anywhere in there airspace and wouldn't hesitate to down any "insurgent" aircraft.
The U.S. pax carriers seem to be avoiding the ZKKP FIR after the MH17 shoot down but this currently airborne FedEx freighter is flight planned through North Korean airspace on B467 between NULAR and KANSU:
FedEx (FX) #155 ? 06-Sep-2014 ? PANC - RKSI / ICN ? FlightAware
There is a recent restriction for U.S. carriers that prohibits operation in North Korean airspace west of 132 East longitude and conveniently does not include B467.