Giving "777" permissions on anything is almost always a bad idea.
In any case, it depends how the stored procedure is creating the files.
For example, if they are being written to an Oracle Directory from PL/SQL, then the permissions of the Oracle DB user will determine their read/write access to the Oracle directory from within Oracle, but this will also depend on the access permissions of the relevant Oracle Unix user for the directory in the file system (because files are actually read/written via an Oracle Unix process).
If your files are being created via Java, then you need to look at how Java modifies file permissions at operating system level.
Joined: Sep 23, 2011
Stored proc writes the file into Oracle directory only. With SYSDBA user login i have created :
Create or replace directory FILE_DIR as <path where Reports are to be created>;
Grant read, write on directory MED_DIR to db_user.