Internet UDP port 1434 is primarily used by Microsoft SQL Server. This port is utilized by the SQL Server Browser service to manage the incoming connections for SQL Server. The service listens on UDP port 1434 and provides information about SQL Server instances installed on the computer. Therefore, any system or software that needs to interact with Microsoft SQL Server may use this port.
UDP port 1434 has been exploited in the past by hackers, particularly in the infamous SQL Slammer worm attack in 2003. This worm propagated rapidly by sending a payload to UDP port 1434, which is used by Microsoft SQL Server Resolution Service. The payload contained a buffer overflow exploit, which allowed the worm to execute arbitrary code on the server. This resulted in a denial of service due to the high network traffic generated by the worm. The attack was so severe that it caused significant slowdowns on the global internet within 15 minutes of its initial detection. Therefore, it's crucial to secure this port to prevent similar attacks in the future.
