Rule Definition
MongoDB does not require authentication by default. Protect your database against unauthorized access by enabling database access control. Enabling access control also allows you to limit actions that particular users can perform on the database.

Remediation
Activate authentication to access the MongoDB database.

Violation Code Sample

var client = new MongoClient("mongodb://localhost")
        or
        var client = new MongoClient("mongodb://localhost:27017"
        or
        var client = new MongoClient("")

Fixed Code Sample

var credential = MongoCredential.CreateMongoCRCredential("mongoDB", "USER", "PWD");

            var settings = new MongoClientSettings
            {
                Credentials = new[] { credential }
            };

            var mongoClient = new MongoClient(settings);
            
            or
            MongoClient constr_OK = new MongoClient("mongodb://USER:PWD@localhost/mongoDB");
            or
            var connectionString = "mongodb://USER:PWD@localhost/mongoDB";

            MongoClient constr_KO = new MongoClient(connectionString);