Software Engineering Institute

When a connection request is made to Oracle for Windows NT, Oracle Database Server creates a new thread listening on a new port and redirects the connection to the new port. This new thread remains in memory listening until the client connects to its port or the Oracle Database Server is restarted.

By making many connection requests to Oracle without connecting to the new threads created to handle the connections, an attacker can force the server to consume all memory with listening threads. Once all server memory is consumed, the next console login attempt will crash the server.

The CERT/CC is currently unaware of a practical solution to this problem.

Enable tcp.validnode_checking and set tcp.invited_nodes and tcp.excluded_nodes to limit Oracle access to trusted hosts.

Set the following parameters in the Oracle Net8 configuration file PROTOCOL.ORA:

tcp.validnode_checking = YES
tcp.invited_nodes = {list of IP addresses}
tcp.excluded_nodes = {list of IP addresses}