CREATE TABLE ABC (A  NUMBER);

insert into abc values(1);
insert into abc values(9);
insert into abc values(13);
insert into abc values(999);

CREATE OR REPLACE PACKAGE ref_cur_tst
IS
-- dummy cursor to get %rowtype below
   CURSOR c1 IS SELECT a FROM abc;
   TYPE t_cur IS REF CURSOR RETURN c1%ROWTYPE;
-- or just use abc%rowtype to match whole table structure.
--  TYPE t_cur IS REF CURSOR RETURN abc%ROWTYPE;

   PROCEDURE get_abc (cv_cur IN OUT t_cur);
END ref_cur_tst;
/

CREATE OR REPLACE PACKAGE BODY ref_cur_tst
AS
   PROCEDURE get_abc (cv_cur IN OUT t_cur)
   IS
   BEGIN
      OPEN cv_cur FOR SELECT a FROM abc;
   END get_abc;
END ref_cur_tst;
/

set serveroutput on;

DECLARE
   a       abc.a%TYPE;
   cv_c1   ref_cur_tst.t_cur;
BEGIN
   ref_cur_tst.get_abc (cv_c1);

   LOOP
      FETCH cv_c1 INTO a;
      EXIT WHEN cv_c1%NOTFOUND;
      DBMS_OUTPUT.put_line (a);
   END LOOP;
   CLOSE cv_c1;
END;
/