You should properly secure the databases, platforms, and servers you use for your Primavera Gateway. You might find the links below helpful when planning your security strategy (not a comprehensive list).
Note: The URLs below might have changed after Oracle published this guide.
Oracle Database 19c Security Guide
https://docs.oracle.com/en/database/oracle/oracle-database/19/dbseg/index.html
Microsoft Windows Server 2016 and 2019 Security Documentation
https://docs.microsoft.com/en-us/windows-server/security/security-and-assurance
Oracle WebLogic
http://www.oracle.com/technetwork/middleware/weblogic/overview/index.html