TNS-12533: TNS:illegal ADDRESS parameters TNS-01103: Protocol specific component of the address is incorrectly specified `LISTENER=(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST=)(PORT = 0)))Ĭonnecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=)(PORT=0))) This configuration will give errors and not allow a Listener named ‘listener’ from starting. You should give a unique name to the Database instance and avoid using the default name “Listener” as the name.Īn additional step is to create a dope Listener named ‘listener’ by following the steps explained. VERIFY THE LOGFILE Disable Default Listener.ĜLOSE SQL*NET ON FIREWALLS AND ISOLATE ON NETWORK.ĚPPLY LATEST SECURITY PATCHES FOR LISTENER.ĞNABLE SECURITY AGAINST NETWORK ON DATABASE LEVEL IN 11G.SET LOCAL_OS_AUTHENTICATION IN LISTENER.ORA.ĜONFIGURE ADMIN_RESTRICTIONS IN LISTENER.ORA.The tnslnsr processes starts with a binary owner, usually the “Oracle” account on UNIX or Linux. tnslnsr starts and verifies the listener.ora and sqlnet.ora files for port numbers and database service names. The lsnrctl is the tool for starting and stopping the listener process (tnslsnr). My Oracle Support Note 1453883.1 for Non-RAC databases My Oracle Support Note 1340831.1 for RAC Databases Oracle’s issued notes for these vulnerability in the following: Oracle recommends that customers apply the solutions to these issues on all database components. These vulnerabilities of the listener also extend to other Oracle products using the Oracle database, including OFM, OEM and Oracle EBS. Oracle Database 11g Release 2, Oracle Database 11g Release 1, Oracle Database 10g Release 2 Sensitive data leak is also possible from the listener.The listener is also vulnerable to any activation of a malicious Operating System command.The listener is vulnerable to denial-of-service(DoS) attacks.However, the settings in the newer versions (11g and 12c) have been changed to ensure that the listener is more secure. Previous versions of the Oracle database (prior to version 10g) had reported security vulnerabilities with the database listener. This, therefore, centers the security of the database on the Listener and is dependent on it. The security of the entire database is dependent on the security of the listener because the Database Listener allows a user to login into the database and is configured in a different manner than the Oracle database.

Maintaining the security of the Database Listener is a critical issue. The Oracle Database Listener module is vital for database operations.

The listener accepts the connection through the default port (1521) or other ports, allowing the client to login into the database. It is, therefore, important to ensure that this component is kept secure from cyber threats and attacks The Oracle Database listener is a module that connects an instance of the Oracle Database and its client.

Oracle database port