Oracle Error : ORA-31003/ORA-06512

The Below Error Appear when you are trying to use dbms_network_acl_admin

ORA-31003: Parent /sys/acls/File_name.xml already contains child entry
ORA-06512: at “SYS.DBMS_NETWORK_ACL_ADMIN”, line 226
ORA-06512: at line 30
ORA-01403: no data found

The Solution Is Simple

exec dbms_network_acl_admin.drop_acl(‘/sys/acls/file_name.xml’);
Commit
Re-Run Script Again.

Thank you
Osama Mustafa

Step By Step Remove Oracle Table Lock

All your query should be done using sys user or system user, after that you need to find Session SID with below query :

SQL> SELECT SESSION_ID
  2  FROM DBA_DML_LOCKS
  3  WHERE NAME = ‘EMP_INFORMATION’;

Where EMP_INFORMATION is Table_name

Output :

SID
___
424

Next step it’s talking about How to find Serial# :

SELECT SID,SERIAL#
FROM V$SESSION
WHERE SID IN (SELECT SESSION_ID
FROM DBA_DML_LOCKS
WHERE NAME = ‘EMP_INFORMATION’)

Output :

SID                SERIAL#
—-                 ——-
424                 1103

Use Alter system To kill this session :
ALTER SYSTEM KILL SESSION ‘SID,SERIALl#’;

Thank you
Osama mustafa


ORA-00838: Specified value of MEMORY_TARGET is too small,

SQL> startup
ORA-00838: Specified value of MEMORY_TARGET is too small, needs to be at least 3072M

make your calculation 3072*1024*1024 = 3221225472

SQL > create pfile=’/u02/backup.init’ from spfile;

edit file and put the above number in memory_target.

SQL > Create spfile from pfile=’/u02/backup.init’ ;

SQL > Startup ;

Thank you
Osama mustafa

SQL92_SECURITY Parameter

SQL> show parameter sql92_

NAME                                 TYPE        VALUE
———————————— ———– ——————————
sql92_security                       boolean     FALSE

SQL92_Security seems it’s parameter related to Security But what is it ? what is the benefits of using this parameter ?

I will describe this example since it will be understandable 🙂

SQL> create user test1 identified by test1 ;

User created.

SQL> grant create session , Create table to test1 ;

Grant succeeded.

SQL>
SQL>
SQL> create user test2 identified by test2 ;

User created.

 SQL> create user test3 identified by test3 ;

User created.

SQL> grant create session to test3 ;

Grant succeeded.

SQL> conn test1/test1 ;
Connected.
SQL> create table new ( id number(20)) ;

Table created.

SQL> BEGIN
    FOR v_LoopCounter IN 1..50 LOOP
    INSERT INTO new (id)
    VALUES (v_LoopCounter);
     END LOOP;
         END;
   / 

PL/SQL procedure successfully completed.

SQL> conn test1/test1 ;
Connected.
SQL>
SQL>
SQL>
SQL> grant update on test1.new to test2 ;

Grant succeeded.

SQL> grant update on test1.new to test3;

Grant succeeded.

SQL> grant select on test1.new to test3;

 SQL> conn test2/test2 ;
Connected.
SQL> update test1.new set id=1 where id=10 ;

1 row updated.

SQL> conn test3/test3 ;
Connected.
SQL> update test1.new set id=10 where id=1 ;

2 rows updated.

Now let’s set SQL92_Security to TRUE and Restart Database and re fire the same query by each user.


Conn test2/test2

SQL>update test1.new set id=1 where id=10 ;

ERROR at line 1:
ORA-01031: insufficient privileges

SQL> conn test3/test3;
Connected.
SQL> update test1.new set id=10 where id=1 ;

2 rows updated.

What Happening Here , Each of users have Privileges on test1.new but why after set SQL92_Security to true test2 not working ?

Simply  SQL92_SECURITY need Update/delete and Select Privileges for the same user if you grant the user one of these privileges then it will be useless.

Amazing 🙂

Thank you
Osama Mustafa

Short Look for Oracle Privileges

Oracle Database Contain two type of privileges one called System and other called Objects each one grant it to use as they need, But interesting entity called Public. it’s more Role than users , and every user created in database assign to Public by default unfortunately nothing can be done to change that. so we can say it’s seems like User Group, so if you grant anything of privileges to public this means that everyone of users database will have this privilege ( System or Object ) So you need to becareful of you doing while dealing with public.

Public is everyone access to database .PUBLIC is an entity that can be granted any privilege and assigned any role. All database users automatically inherit all the rights assigned to PUBLIC. It’s a simple concept designed for convenience. Granting permissions to PUBLIC is easy to do, and often the easiest way to get a system working, however, the security implications of using the PUBLIC group to assign permissions are significant.PUBLIC should be treated with care and used sparinglyPUBLIC should be treated with care and used sparingly.

Before go deeply with this subject we need to understand Role and Privileges in oracle database,as you all know Oracle Privileges control the rights to see, you could Modify, create or alter database depend on privileged you have,as i mention earlier two Privileges in database exists System and Object.

System privileges are not related to any specific object or schema. Object privileges are just the opposite, those that are directly related to a specific object or schema.check the examples below

System Privilege
Object Privilege
GRANT ANY PRIVILEGE
GRANT
ALTER ANY ROLE
ALTER
ALTER DATABASE
SELECT

to check system privileges in database you need to check the following DBA_ DICTIONARY :

SQL> desc dba_sys_privs;
 Name                                      Null?    Type
 —————————————– ——– —————————-
 GRANTEE                                   NOT NULL VARCHAR2(30)
 PRIVILEGE                                 NOT NULL VARCHAR2(40)
 ADMIN_OPTION                                            VARCHAR2(3)

Sample data From table :

GRANTEE                        PRIVILEGE                                ADM
—————————— —————————————- —
SYS                            CREATE OPERATOR                                 NO
SYS                            EXECUTE ANY OPERATOR                     NO
SYS                            CREATE DIMENSION                                NO
SYS                            ADMINISTER RESOURCE MANAGER     NO

Another example i want to check scott and his system privileges :

SQL> select * from dba_sys_privs where GRANTEE = ‘SCOTT’;
GRANTEE                        PRIVILEGE                                ADM
—————————— —————————————- —
SCOTT                          UNLIMITED TABLESPACE                     NO

Now Let’s Talk About Object Privileges :

SQL> desc dba_tab_privs;
 Name                                      Null?    Type
 —————————————– ——– —————————-
 GRANTEE                                   NOT NULL  VARCHAR2(30)
 OWNER                                     NOT NULL  VARCHAR2(30)
 TABLE_NAME                          NOT NULL  VARCHAR2(30)
 GRANTOR                                 NOT NULL VARCHAR2(30)
 PRIVILEGE                                 NOT NULL VARCHAR2(40)
 GRANTABLE                                                  VARCHAR2(3)
 HIERARCHY                                                   VARCHAR2(3)

more complex huh ? Read Oracle Documentation Here

SQL> select OWNER, TABLE_NAME, PRIVILEGE, GRANTABLE from dba_tab_privs where GRANTEE = ‘SCOTT’;
no rows selected.

What about Roles ? as you we knows Oracle Comes with Pre defined such as DBA, Resource , and connect also you can create your own Role which is Set of privileges to manage Users Privileges.
 user can be a member of more then one role, and roles can even be members of other roles.
Users in company leaves their jobs , Travel or even don’t need privileges in futures Create Oracle Role will make all this Manage is easy since . Privileges are then granted only to the roles, never to a specific user,if the privileges ever change, they are changed on the role and automatically take effect for all users with the role.and you check

SQL> desc dba_roles ;
 Name                                      Null?    Type
 —————————————– ——– —————————-
 ROLE                                      NOT NULL         VARCHAR2(30)
 PASSWORD_REQUIRED                                  VARCHAR2(8)

For information about this table you can Read Oracle documentation here.

SQL> desc dba_role_privs
 Name                                      Null?    Type
 —————————————– ——– —————————-
 GRANTEE                                                   VARCHAR2(30)
 GRANTED_ROLE                  NOT NULL VARCHAR2(30)
 ADMIN_OPTION                                       VARCHAR2(3)
 DEFAULT_ROLE                                       VARCHAR2(3)

The above table checks the privileges granted to Role, you can refer to Oracle Documentation here
check the below query to determine Which User Have DBA Role :

SQL> select GRANTEE, ADMIN_OPTION, DEFAULT_ROLE from dba_role_privs where
GRANTED_ROLE = ‘DBA’;  2
GRANTEE                        ADM DEF
—————————— — —
SYS                                  YES YES
SYSMAN                         NO  YES
SYSTEM                         YES YES

As conclusion Public can be Granted any of Roles or users,While it is easy and fully supported to grant roles to PUBLIC i don’t recommended to do that  give one case why to do that ?
Check the user who has Public  :

SQL> select * from dba_role_privs where GRANTEE = ‘PUBLIC’;
no rows selected

And this exactly what we want not Public roles to any users.
Thank you 
Osama Mustafa

Disable Auditing Using Oradebug

in 2011 Laszlo Toth Show some Oracle tricks to disable Auditing In Oracle Database included with SYS auditing using simple command Called oradebug, Just as note oradebug is undocumented in all oracle versions and if you have sysdba role privileges you can do a lot of things with this command :

the below is the demonstration :

sqlplus / as sysdba

SQL> — get the offset for oradebug

SQL> select fsv.KSMFSNAM,sga.*
from x$ksmfsv fsv, x$ksmmem sga
where sga.addr=fsv.KSMFSADR
and fsv.ksmfsnam like ‘kzaflg_%’;

KSMFSNAM ADDR INDX INST_ID KSMMMVAL
—————- ———- ———- —————-
kzaflg_ 0000000060031BB0 26652 1 0000000000000001

SQL> show parameter audit;

NAME TYPE VALUE
———————————— ———– ——————————
audit_file_dest string /u01/app/oracle/admin/PSALES/adump
audit_sys_operations boolean TRUE
audit_syslog_level string
audit_trail string DB, EXTENDED

SQL> oradebug poke 0x60031bb0 1 0
BEFORE: [060031BB0, 060031BB4) = 00000001
AFTER: [060031BB0, 060031BB4) = 00000000

Just as note with oradebug you Audit vault become useless. another tricks that we can use oradebug to call Database command using OS 🙂 

SQL> oradebug call system    “ls -la >/tmp/hacktivity.txt”

Thank you
Osama mustafa

Oracle Security –> Where to Start ? What to do ?

When you start reading the title you start thinking of Race, Mostly you can think of that since technology going fast, But my article it’s not about race it’s talking about where should i look when i secure my database what should i secure ? I post another articles talking about security and how to secure your database what is the benefits of securing database ? I will try to mention the most important points to secure and protecting database specially internal users.

Database is complex, so DBA ( Database administrator ) must understand potential security impacts  and The three components Triangle which i mentioned before in “Top ten Threats to Database” For example when DBA looking for availability they ignore right configuration which cause security vulnerability and this can lead to expose confidential data. it’s not about database if you have application you need to take over and start secure this application. but what can i do ? Where to start and how to start ? 

The Basic Steps to Start like i mentioned in my post “basic Steps to Secure Oracle”  is to discuss the risk management that lead to this, and you can secure your database by looking for the below keys  :

  • Auditing
  • Database Configuration
  • Access to database
  • Authentication 


I need to Remind you in something Secuirty Not means i will protect my database 100% it’s way to prevent attacks and make it harder, But what if the attackers get in database 

Auditing 


Auditing allow us to monitor database users,or anything that happened on database,first audit_sys_operations parameter should be set to TRUE to monitor sys user operation. The audit_trail parameter ( DB|OS) where the location of Audit files will goes ? For example Audit Files could be written on Database  or On File System if you set this parameter to OS. let’s talk about database here :

SQL> SELECT * FROM dba_obj_audit_opts;

SQL> SELECT * FROM dba_priv_audit_opts;
SQL> SELECT * FROM dba_stmt_audit_opts

 you cannot enable auditing to monitor all database activities but at least you can enable it for action such as create session , by fire this command —> audit create session;

What i love in 11gR2 documentation is that Oracle has create it’s own list for recommended auditing list which mean you should enable it. another type of auditing called FGA allow you to create policy to run on certain event for example when scott read from table emp column Sal i want to record this transaction on table. simple way read more about : —> DBMS_FGA.ADD_POLICY, and check this event to you need to have access on sys.fga$.

After you enable auditing it’s very important to Create your own reports to monitor database.Oracle gives you products to centralize this audit logs called audit vault the benefits of this products it’s automatically clean up the old data ( only if transferred to server ) and remove them.

 Database Configuration

When start talking about secure configuration lot of steps came to my mind, but i will try make simple since i can’t cover everything in this topics, i will divide it to more than one topics and Post on my blog, as you know in this part you have to look at network, Listener , Client side , Parameters , and Backup i am apology if i forget something, each part of this compentents are very important but let’s talk about parameters as we all know Database have something called spfile/pfile which is parameter file for database, Some of parameter set for TRUE by default while i don’t need them vice versa, change the value of this parameter are important to avoid any Weakness in the futures some of this parameters are :

  • OS_ROLES —-> Should be False 
  • os_authent_prefix —> Ops$ 
  • o7_dictionary_accessibility –> Should be False 
  • audit_sys_operations –> Should be True
  • Global_name —> Should be True
  • Remote_listener —> use it only if you need it
  • remote_login_passwordfile –> none 
  • sec_case_sensitive_logon –> Should be True
  • sql92_security —> Should be True 
  • remote_os_roles –> Should be False

lot of parameters, but i mention some of them.

Also Don’t forget to secure your Listener set password for listener, change default port simple steps but make you avoid future attack.
Another point don’t forget to patch your database check oracle site for you new CPU and PSU patch this will fix security vulnerability, Read More here.
 Another way also to secure configuration using Database firewall ( i will post topic about it later ) , network firewall and create policy inside the company.

Access to database


in each topic i post i am talking about this, i am will mention it in every topics in the future it’s important and the most of hacking cases happened because user has privileges more than he needs why ?  is your data not important !!! when the user authenticated to database first thing you need to check what this user allow to do ? especially for developers and application user ( dose he need DBA role to execute procedure ) 

 SQL> SELECT * FROM dba_sys_privs;
SQL> SELECT * FROM dba_role_privs;
SQL> SELECT * FROM dba_col_privs;
SQL> SELECT * FROM dba_tab_privs;

it’s not only about privileges , Create Development , test and QA database is important not everything works on Production is correct , create new users with different privileges some of them to monitor some of them to manege, Boring but Useful , Don’t forget Database links i mention before in my topics about database link security and how this could effect on your database, well Links create new privileges escalation, Review database link and check who access to them , who use them , how he use them and is it valid any more ?

SQL> SELECT * FROM sys.link$;

as conclusion you have to check user privileges , Application users , Users , Database links and Create new instance for new jobs ,  not all company spend money to secure database but why should i buy new products while i am not doing the basic steps before that , it’s maybe avoid company small fortune and they will loves for that.

Authentications

Well , I should mention it first but it’s all about security why should i care ? the first thing happened in database is authentications obtaining user information , Password the problem is The mutli way for doing that make risk is high you have OS authentications …. etc check my post about “Effect of Default Password” and you will be surprised what i can do with default password !!! in 11g you can check the Deafult password in new View :

SQL >  select * from dba_users_with_defpwd;

But you can’t also forget about

SQL > Select * from dba_users;

each of them has different job, not everything mentioned in dba_users_with_defpwd , Once you change password and Create new one ( hard to guess ) now you need to provide new rules for password here we start talking about profiles

SQL > Select * from dba_profiles ;

Example for how to create profile in oracle :

CREATE PROFILE Example LIMIT
  FAILED_LOGIN_ATTEMPTS 3 
  PASSWORD_LOCK_TIME 5    
  PASSWORD_LIFE_TIME 30   
  PASSWORD_GRACE_TIME 3   
  PASSWORD_REUSE_TIME 120 
  PASSWORD_REUSE_MAX 10   
/

Also read Oracle documentation here.

I will take later about Authentications type In oracle provided with Examples and talk about which one is more secure and when i need to use it ?

Don’t forget that Oracle Provide Password complexity that located in $ORACLE_HOME/rdbms/admin with Script called –> utlpwdmg.sql just run it / as sysdba and new rules will be applied to passwords you can create your own one. but this script do the below

  • The password contains  eight characters or more.

  • Password not same as username.
  • password should not be simple 
  • password should contain Numeric and alphabetic.
  • password should be different from the last password.

and other’s features simple and amazing Right 🙂

as conclusion i will post more topics about security and more examples will be waiting, and i wish it’s useful and simple, i can’t cover all things in one article i will be huge i will try to do my best.

Thank you
Osama Mustafa

ORA-1461 encountered when generating server alert SMG-3500

Two bug could be related to this error  Bug 6085625 and unpublished bug 6452485.

to fix the above bug you need to apply  Patch 6602742 or Patch 6602482 Depend on your case

as workaround you have to optiosn :

A. Flushing the shared pool can help remove the problem cursor from the shared pool.
B. Or set SESSION_CACHED_CURSORS = 0

Thank you
Osama mustafa

ORA-0131: insufficient privileges/could not validate ASMSNMP password

This error related to ASM instance, Usually it’s happened when you are trying to create dbconsole the solution is simple and not that complicated just follow the below instruction.

Choose one of Rac ( Real Application Cluster ) and fire the below command under grid user :

 orapwd file=/u01/app/11.2.0/grid/dbs/orapw+ASM password=

Now Move the  (orapw+ASM) to other nodes using scp and any FTP software as you like. to know about scp here. check the below example :

scp orapw+ASM :/u01/app/11.2.0/grid/dbs/

Back to Oracle User :

export ORACLE_SID=+ASM1
export ORACLE_HOME=/u01/app/11.2.0/grid
$ sqlplus / as sysasm
SQL>create user asmsnmp identified by ;
SQL> grant sysdba to asmsnmp;

Thank you
Osama Mustafa

Sys Password and Alter User Privileges

While I am browsing i found this topic which is really amazing and Useful if you are interested securing your database, I mentioned before in my topics to secure database you need to start with simple steps first the below is one of them :

SQL> CREATE or REPLACE TRIGGER prohibit_alter_SYSTEM_SYS_pass
AFTER ALTER on SCOTT.schema
BEGIN
IF ora_sysevent=’ALTER’ and ora_dict_obj_type = ‘USER’ and
(ora_dict_obj_name = ‘SYSTEM’ or ora_dict_obj_name = ‘SYS’)
THEN
RAISE_APPLICATION_ERROR(-20003,
‘You are not allowed to alter SYSTEM/SYS user.’);
END IF;
END;
/

Trigger created.

SQL> conn scott/tiger
Connected.

SQL>alter user system identified by new_password;
alter user system identified by new_password
*
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-20003: You are not allowed to alter SYSTEM/SYS user.
ORA-06512: at line 5

SQL> alter user sys identified by new_password;
alter user sys identified by new_password
*
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-20003: You are not allowed to alter SYSTEM/SYS user.
ORA-06512: at line 5