Ora TNS Password tester fist checks if password on Oracle database server listener exists or not. If it doesn't exist then it will inform user that no password is set on the listener. If password on the listener exists then this utility will try to retrieve listener password by applying dictionary attack on the listener. Listener's security is important because if somebody is able to connect to the listener and shut it down, this will create a denial of service situation where Database will become offline and legitimate users requests and queries will not be answered. Many Administrators tend to overlook listener security and basic purpose of this utility is to proof this concept that listener's security is important for oracle database security.