Information
Changing the default port used by MongoDB makes it harder for attackers to find the database and target it.
Standard ports are used in automated attacks and by attackers to verify which applications are running on a server.
Solution
Change the port for MongoDB server to a number other than 27017
In mongod.conf edit the below lines
# network interfaces
net:
port: $Orginasation Defined port
bindIp: $Orginasation Defined IP
Impact:
Hackers frequently scan IP addresses for commonly used ports, so it's not uncommon to use a different port to "fly under the radar". This is just to avoid detection, other than that there is no added safety by using a different port.