How do travel apps handle restricted areas and borders on their maps?

On our maps we see the terrain, roads, trails, various borders and points on the maps. Some borders show protected or restricted territories but the travel apps often don't explain what exactly are the rules for crossing. Besides, the rules can be changed (which requires almost "real-time" checking), and sometimes the restricted area or it's precise border is not on the map at all.

I ran into exactly this while researching a route through a protected area in the Rila Mountains, Bulgaria. There was a clearly marked road on the map, but when I arrived I found that access was forbidden.

So how do travel and mapping platforms identify, check, and actualize such restrictions? Do they use official sources, local institutions, terrain assistants, or signals from random tourists?