如何移除和重新安裝Oracle JVM步驟

前言

自從2018年8月10日發表Oracle JVM漏洞，攻擊者只要使用一些Java語法就可以取得主機控制權，開始有人詢問如何查詢DB內相關的Java物件和移除Oracle JVM的方法。

1.查詢Oracle DB內有關聯的JAVA物件

select owner, status, count(*) from all_objects

        where object_type like '%JAVA%' group by owner, status;

如果要查詢元件名稱

select owner, object_name from all_objects

        where object_type like '%JAVA%';

2.確認移除OJVM的必要環境條件

Shared Pool 至少 96 MB 空間. 
     Java Pool 至少 50 MB 空間 
     SYSTEM tablespace 至少 70 MB 空間 
     SYSTEM RBS 至少 100 MB 空間

3.編輯移除的 SQL Script並執行

vi  remove_ojvm.sql 加入以下的文字

spool remove_ojvm.log

set echo on

connect / as sysdba

startup mount

alter system set "_system_trig_enabled" = false scope=memory;

alter system enable restricted session;

alter database open;

@?/rdbms/admin/catnoexf.sql

@?/rdbms/admin/catnojav.sql

@?/xdk/admin/rmxml.sql

@?/javavm/install/rmjvm.sql

truncate table java$jvm$status;

select * from obj$ where obj#=0 and type#=0;

delete from obj$ where obj#=0 and type#=0;

commit;

select owner, count(*) from all_objects

where object_type like '%JAVA%' group by owner;

select obj#, name from obj$

where type#=28 or type#=29 or type#=30 or namespace=32;

select o1.name from obj$ o1,obj$ o2

where o1.type#=5 and o1.owner#=1 and o1.name=o2.name and o2.type#=29;

shutdown immediate

set echo off

spool off

exit

4. 確認執行結果

SQL> select owner, object_name from all_objects

        where object_type like '%JAVA%';  2

5.如果要重新安裝OJVM

vi init_ojvm.sql 加入以下內容並執行

-- Start of File init_ojvm.sql

spool full_jvminst.log;
set echo on
connect / as sysdba
startup mount
alter system set "_system_trig_enabled" = false scope=memory;
alter database open;
select obj#, name from obj$
where type#=28 or type#=29 or type#=30 or namespace=32;
@?/javavm/install/initjvm.sql
select count(*), object_type from all_objects
where object_type like '%JAVA%' group by object_type;
@?/xdk/admin/initxml.sql
select count(*), object_type from all_objects
where object_type like '%JAVA%' group by object_type;
@?/xdk/admin/xmlja.sql
select count(*), object_type from all_objects
where object_type like '%JAVA%' group by object_type;
@?/rdbms/admin/catjava.sql
select count(*), object_type from all_objects
where object_type like '%JAVA%' group by object_type;
@?/rdbms/admin/catexf.sql
select count(*), object_type from all_objects
where object_type like '%JAVA%' group by object_type;
shutdown immediate
set echo off
spool off
exit
-- End of File init_ojvm.sql