You might be surprised to know that obtaining an overflight and landing permit for North Korea is actually pretty straight forward, as long as you have all the required paperwork in place.
All operators, regardless of what type of operation they are conducting, will require an overflight permit. The CAA requires basic information: Aircraft type/registration, DOF, Entry/Exit Point etc. Processing time for this permit is generally 3 business days, however if needed for a last minute operation a permit can generally be expedited. Permits are valid for 72hrs. In case there is a change to entry/exit points, routing while inside Pyongyang FIR (ZKKP), or a delay in excess of 72 hrs a revision will need to be submitted. It's also very important to note that it is only allowed to fly on the airways that are approved
Landing permits can be obtained but require a minimum of 7 business days to process. Before the application goes into the CAA it is really important to ensure that all the required paperwork is in order so any delays can be avoided. In addition to the documents above the CAA will require a COR, COA, valid insurance, copies of all crew members licenses, passports, and North Korean visas, information, and contact details of the receiving party in Pyongyang. It is also important to note that all arrivals and departures must be from Pyongyang (ZKPY). Visas must also be prearranged as there are no visa's on arrival.
Recent missile operations have been taking place in off the shores of North Korea, creating a lot of concern from the global community. None of the missiles are being directed at an civil aviation aircraft, it is worth noting that most of the missiles are following a North/South pattern - which is also the direction of most of the international airways. Now some countries have issued their own alerts (SFAR 79), advising operators to stay clear of ZKKP, but it is advised to check with you CAA prior to commencing any flights.