Read Access On Oracle Database Trace Files .-- _trace_files_public hidden parameter

 

The " _trace_files_public" parameter is a hidden parameter whose default value is false and once it's set to true that will allow all users accessing the server where the oracle database is hosted will be able to read the trace files. 

This is not recommended as per CIS security standards however in some environment , application team do come up  with requirements . 

Since this is a hidden parameter and your query its current setting following X$ tables need to be queried:

select A.ksppinm, B.ksppstvl

from sys.x$ksppi a,sys.x$ksppcv b

where A.indx=B.indx

and A.ksppinm like '\_%trace_files_public' escape '\';

To change the value of this parameter, it will need a database bounce after running:

alter system set "_trace_files_public" = TRUE scope=spfile;

Other Way is to handle from server level using umask 

umask 0002 this will give u 664 permission

umask 0000 this will give u 666 permission