2.1.1 Ensure 'extproc' Is Not Present In 'listener.ora'
Information
extproc should be removed from the listener.ora to mitigate the risk that OS libraries can be invoked by the Oracle instance. extproc allows the database to run procedures from OS libraries. These library calls can, in turn, run any OS command.
Solution
To remediate this recommendation, remove extproc from the listener.ora file. Instead of relying on the EXTPROC feature in Oracle to access external libraries, you can use a database directory to directly access the library files stored within the database server's file system, allowing you to execute code from those libraries within your PL/SQL code without going through a separate external process.