Title
                                                            31/3/2002
                   Oracle9i TSN Vulnerable to a DoS Attack

   Summary
  A security vulnerability in Oracle9i ("Unbreakable") Database Server has been found, the vulnerability 
  would allow remote attackers to cause the server's TSNLISTEN service to crash disallowing any 
  legitimate requests from being handled by the remote server.

   Details
  Vulnerable systems:
  Oracle version 9.0.1.1

  In order to crash Oracle9i all you need to do is send ONE TCP packet (#$00 = 1 byte) to 1521 port. To 
  restore server functionality you must restart the TSNLISTEN service.