Accessing a user when you don’t know the password

25/03/2016 4 Comments

There are times that you may need to logon to a database user, probably a schema owner to do a release, but you don’t know the password. You may not be able to (easily) change the password as it could be embedded in application connect strings or worse.

If may not be possible simply to change your session using alter session set current_schema=<schema-to-be-changed>; to auto-prefix all of your selects with the schema, especiually if the release references “USER_” views, which is unaffected by the session setting.

You need to become the account.

So, what you need to do is record the current password encryption, change the password, logon and do your maintenance, logoff and change the password back!

And this is how you do it:
Create an account:

04:38:35 SYS @ ORCL01 > create user hackme identified by password1;

User created.

04:38:35 SYS @ ORCL01 > grant connect,resource to hackme;

Grant succeeded.

Grab the encryption.This is stored in SYS.USER$.SPARE4 plus SYS.USER$.PASSWORD:

04:38:35 SYS @ ORCL01 > select name,'alter user '||name||' identified by values '''||spare4||';'||password||''';' command from sys.user$ where name = 'HACKME'
04:38:35   2  /

NAME       COMMAND
---------- ------------------------------------------------------------------------------------------------------------------------
HACKME     alter user HACKME identified by values 'S:59F38E64D3914BB9396C5D4B968380676333EA7CB34F2471A85C4770A7BA;H:2D3693D1357CF012D9A11EFE3D792C0C;T:B2261F70475F3BD6173867C68427E346C53216E3EC305121DDAF4E13E72E6889DF1E314934F3C5F46E5F12B82D8AC144955C937413FD192904A2762D66B31A872429AB78E72AFC2BC4101E68DB5903A6;4345E749C3EBB34A';

Now we can change the password, logon with the new password, logoff back to a DBA and change it back using the previously captured command

04:38:35 SYS @ ORCL01 > alter user hackme identified by hacker;

User altered.

04:38:35 SYS @ ORCL01 > connect hackme/hacker;
Connected.

04:38:35 HACKME @ ORCL01 > show user
USER is "HACKME"

04:38:35 HACKME @ ORCL01 > connect sys/oracle as sysdba
Connected.

04:38:35 SYS @ ORCL01 > alter user HACKME identified by values 'S:59F38E64D3914BB9396C5D4B968380676333EA7CB34F2471A85C4770A7BA;H:2D3693D1357CF012D9A11EFE3D792C0C;T:B2261F70475F3BD6173867C68427E346C53216E3EC305121DDAF4E13E72E6889DF1E314934F3C5F46E5F12B82D8AC144955C937413FD192904A2762D66B31A872429AB78E72AFC2BC4101E68DB5903A6;4345E749C3EBB34A';
User altered.

04:38:57 SYS @ ORCL01 > conn hackme/password1
Connected.

Magic!

You can also use DBMS_METADATA to get the encryption;

04:39:08 SYS @ ORCL01 >  set long 10000

04:39:08 SYS @ ORCL01 >  select dbms_metadata.get_ddl('USER','HACKME') command from dual;

COMMAND
--------------------------------------------------------------------------------

CREATE USER "HACKME" IDENTIFIED BY VALUES 'S:F299C40420DD341AF9AC4AC89C59A2BB1DFCEF01DB5E3C2B5AD837100117;H:2D3693D1357CF012D9A11EFE3D792C0C;T:101F2A697CA5F77B089C4ECA8EE2DDB82E340D46FE60712445699C5715C3C71BA06532F52CFA987076B51254E5E5A565C44E9F7479018F924707F30874A0BF958D1B8935B7434CF993D3346FF53F28B4;4345E749C3EBB34A'
DEFAULT TABLESPACE "USERS"
TEMPORARY TABLESPACE "TEMP"

Please read the COMMENTS to learn about Proxy Accounts – an (admin) alternative from 10G onwards!

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Filed under Administration, audit, oracle, Problem Solving, Security Tagged with , , , , , , , , , , , , ,

Releasing to schemas the easy way

28/09/2014 Leave a comment

Sometimes we occasionally just miss the obvious, for years. Just noticed that an easy way to release code to a particular schema is to login as your normal DBA user (USER1) [as preferred by audit], use the alter session command to switch to point to the release schema (USER2) and run your DDL. Oracle behaves, from an object-owner perspective, as if you are logged-in as the schema owner without all the negative aspects of actually having to login as the schema owner or prefix all object with the schema owner.

This is particularly useful when you have multiple schemas within the database and you are releasing to more than one schema at once.

 

e.g.

sqlplus USER1@ORCL

SQL*Plus: Release 11.2.0.1.0 Production on Wed Sep 17 12:17:36 2014

Copyright (c) 1982, 2010, Oracle. All rights reserved.

Enter password:

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Data Mining and Real Application Testing options

12:17:38 USER1@ORCL>select owner,table_name from dba_tables where table_name = 'N1';

no rows selected

12:17:46 USER1@ORCL>create table n1 (c1 date);

Table created.

12:17:56 USER1@ORCL>select owner,table_name from dba_tables where table_name = 'N1';

OWNER                          TABLE_NAME
------------------------------ ------------------------------
USER1                          N1

12:17:57 USER1@ORCL>alter session set current_schema=USER2;

Session altered.

12:18:08 USER1@ORCL>create table n1 (c1 date);

Table created.

12:18:11 USER1@ORCL>select owner,table_name from dba_tables where table_name = 'N1';

OWNER                          TABLE_NAME
------------------------------ ------------------------------
USER2                          N1
USER1                          N1

 

 

Filed under Administration, audit, SCHEMA Tagged with , , ,