Information
One class of man-in-the-middle, or session hijacking, attack involves the adversary guessing at valid session identifiers based on patterns in identifiers already known.
The preferred technique for thwarting guesses at Session IDs is the generation of unique session identifiers using a FIPS 140-2-approved random number generator.
However, it is recognized that available DBMS products do not all implement the preferred technique yet may have other protections against session hijacking. Therefore, other techniques are acceptable, provided they are demonstrated to be effective.
Solution
Edit the %MongoDB configuration file% to ensure the net.tls.mode option is included and set to the value requireTLS as shown below:
net:
tls:
mode: requireTLS
Stop/start (restart) and mongod or mongos using the %MongoDB configuration file%.
Further documentation is here:
https://docs.mongodb.com/v4.4/tutorial/configure-ssl/.