Sql server execute permission; failure to apply permissions - sql-server

I've just migrated from SQL2000 to SQL2008 and I have started getting an execute permission issue on a stored proc which uses sp_OACreate.
The rest of the system works fine with the db login which has been setup and added to the database.
I've tried:
USE master
GO
GRANT EXEC ON sp_OACreate TO [dbuser]
GO
But this fails with the following error:
Msg 15151, Level 16, State 1, Line 1
Cannot find the user 'dbuser', because
it does not exist or you do not have
permission.
I'm logged into the server as sa with full permissions. I can execute a similar sql statement and apply the permissions to a server role, however not a login/user.
How do I apply the changes to the specific user/login?
I can apply the permissions to the public role and it resolves my issue; however this seems to be a security issue to me which I don't really want to apply to the live server.

Leading on from John's answer I checked the user listings on the Master database and my user wasn't there. Whether it had been deleted or lost some how I don't know. Something may have gone crazy with the migration of the dbs to the new server instance.
Anyway; re-creating the user and associating it to the specific login enabled me to run the following statements on the master database to allow for the execution of the stored procs.
USE MASTER
GO
GRANT EXECUTE ON [sys].[sp_OADestroy] TO [dbuser]
GO
GRANT EXECUTE ON [sys].[sp_OACreate] TO [dbuser]
GO
GRANT EXECUTE ON [sys].[sp_OAMethod] TO [dbuser]
GO
GRANT EXECUTE ON [sys].[sp_OASetProperty] TO [dbuser]
GO
Thanks for all the help and pointers. Hope this helps other people in the future.

The error suggests that the User "dbuser" does not exist in the master database.
I assume the user exists within the master database?
You can check by using the following T-SQL
USE MASTER;
GO
SELECT *
FROM sys.sysusers
WHERE name = 'dbuser'
If the user turns out not to exist, simply use the CREATE USER statement and create a user called "dbuser". The user will automatically be mapped to a Login of the same name, provided one exists.

Your problem could be related to orphaned users.
Try
USE MASTER
GO
EXEC sp_change_users_login 'Report'
This will return one row per orphaned user name. Then,
EXEC sp_change_users_login 'Update_One', 'dbuser', 'dbuser'

Here is some code I'm using the verify that (current user) has EXECUTE permission on sp_OACreate etc:
use master;
select state_desc,name from
sys.database_permissions a
left join
sys.all_objects b
on a.major_id = b.object_id
where name like 'sp_OA%';
As pointed out by #John Sansom and #WestDiscGolf the user has to exist in the Master database and the execution rights must granted in the Master database, hence use Master is required. The query above will return records if the user has execute permissions and empty set if they do not. (Execution in the user database will also return empty set.)
I couldn't figure out a way check these permissions using fn_my_permissions, which is supposedly the right tool for jobs like this.

Check if your user has permissions for the database you use. You can do this by Security -> Logins -> Select User and open the properties window. Then select "User Mapping" from the right menu. Now check the databases that you want the given user to have access to. After that select from the bottom part of the window "Database role membership" and check "db_owner". Now the user will be the owner of the database and will be able to execute queries, store procedures and so on.
UPDATE:
Add user for the database by selecting your database -> security -> users -> right click "New User"
Or you can use this query
CREATE LOGIN AbolrousHazem
WITH PASSWORD = '340$Uuxwp7Mcxo7Khy';
USE AdventureWorks2008R2;
CREATE USER AbolrousHazem FOR LOGIN AbolrousHazem;
GO
Here are more details http://msdn.microsoft.com/en-us/library/ms173463.aspx

Related

SQL owner chaining

Basically I have a front end application called AdminProgram. In SQL Server I have a role called AdminProgramUsers.
Now this role has permissions to various SPs and the like but, crucially, there is no select permission on any table. Everything they see or modify is done through SPs.
Now I've just written a new SP for them. I have had no choice but to use dynamic SQL, that is constructing the actual SQL query in a String variable called #FinalQuery and then running EXECUTE #FinalQuery.
Now initially I was getting a lot of user doesn't have access to the tables, needed to either grant SELECTs to the columns in question, but that solution won't work due to internal politics.
The other thing I seem to understand is that I need to use EXECUTE AS somehow. I have Googled, but I'm struggling to get this right.
And to pre-emptively answer a couple of questions, there is no option but to use dynamic SQL in this SP much to my displeasure, we're talking about SQL Server 2005 and there will be no way of signing any SPs with certificates (mainly as the DBA will flip a nut at the prospect of anything complicated).
So... I think the answer lies somewhere in EXECUTE AS with ownership chaining... but I need to know how to do it... assuming that the role available is AdminProgramUsers...
The current solution I have is:
CREATE SP MySp AS
DECLARE #FinalTable (columns)
DECLARE #FinalQuery
SET #FinalQuery = "EXECUTE AS CALLER
SELECT blah blah"
INSERT #FinalTable
EXECUTE (#QueryString) AS user ='AdminProgramUsers'
Do some more processing on #FinalTable
Select * from #FinalTable
The error I get is:
Unexpected Error in My Sp
Cannot execute as the database principal because the principal "AdminProgramUsers" does not exist, this type of principal cannot be impersonated, or you do not have permission.
here is an excerpt from ms documentation about execute on sql server 2005:
The user or login name specified in AS { LOGIN | USER } = ' name '
must exist as a principal in sys.database_principals or
sys.server_principals, respectively, or the statement will fail.
Additionally, IMPERSONATE permissions must be granted on the
principal. Unless the caller is the database owner or is a member of
the sysadmin fixed server role, the principal must exist even when the
user is accessing the database or instance of SQL Server through a
Windows group membership.
in your code you feed the execute a role but a user or login is expected instead.
the above text is not very clear if you don't read this:
LOGIN
Specifies the context to be impersonated is a login. The scope
of impersonation is the server.
USER
Specifies the context to be
impersonated is a user in the current database. The scope of
impersonation is restricted to the current database. A context switch
to a database user does not inherit the server-level permissions of
that user.
you can specify a user or a login as impersonation context; a role is neither a login nor a user.

The EXECUTE permission was denied on the object 'xxxxxxx', database 'zzzzzzz', schema 'dbo'

I'm having problems executing a function.
Here's what I did:
Create a function using SQL Server Management Studio. It was successfully created.
I then tried executing the newly created function and here's what I get:
The EXECUTE permission was denied on
the object 'xxxxxxx', database
'zzzzzzz', schema 'dbo'.
Sounds like you need to grant the execute permission to the user (or a group that they a part of) for the stored procedure in question.
For example, you could grant access thus:
USE zzzzzzz;
GRANT EXEC ON dbo.xxxxxxx TO PUBLIC
Best solution that i found is create a new database role i.e.
CREATE ROLE db_executor;
and then grant that role exec permission.
GRANT EXECUTE TO db_executor;
Now when you go to the properties of the user and go to User Mapping and select the database where you have added new role,now new role will be visible in the Database role membership for: section
For more detail read full article
In SQL Server Management Studio, go to security->schema->dbo:
Double-click dbo, select the Permissions page, then click the "View database permissions" link in blue:
Select the user for whom you want to change permissions, and look for the "Execute" permission under the "explicit" tab:
Choose the appropriate permission by checking the appropriate box.
you need to run something like this
GRANT Execute ON [dbo].fnc_whatEver TO [domain\user]
This will work if you are trying to Grant permission to Users or roles.
Using Microsoft SQL Server Management Studio:
Go to: Databases
Right click on dbo.my_database
Choose: Properties
On the left side panel, click on: Permissions
Select the User or Role and in the Name Panel
Find Execute in in permissions and checkmark: Grant,With Grant, or Deny
Giving such permission can be dangerous, especially if your web application uses that same username.
Now the web user (and the whole world wide web) also has the permission to create and drop objects within your database. Think SQL Injection!
I recommend granting Execute privileges only to the specific user on the given object as follows:
grant execute on storedProcedureNameNoquotes to myusernameNoquotes
Now the user myusernameNoquotes can execute procedure storedProcedureNameNoquotes without other unnecessary permissions to your valuable data.
You don't have the right to execute it, although you have enough permissions to create it.
For more information, see GRANT Object Permissions (Transact-SQL)
If you have issues like the question ask above regarding the exception thrown when the solution is executed, the problem is permission, not properly granted to the users of that group to access the database/stored procedure. All you need do is to do something like what i have below, replacing mine with your database name, stored procedures (function)and the type of permission or role or who you are granting the access to.
USE [StableEmployee]
GO
GRANT EXEC ON dbo.GetAllEmployees TO PUBLIC
/****** Object: StoredProcedure [dbo].[GetAllEmployees] Script Date: 01/27/2016 16:27:27 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER procedure [dbo].[GetAllEmployees]
as
Begin
Select EmployeeId, Name, Gender, City, DepartmentId
From tblEmployee
End
here is how to give permission for one user not public,
Direct Query:
Use MyDatabase
Grant execute on [dbo].[My-procedures-name] to [IIS APPPOOL\my-iis-pool]
Go
You can give everybody execute permission:
GRANT Execute on [dbo].your_object to [public]
"Public" is the default database role that all users are a member of.
If you make this user especial for a specific database, then maybe you do not set it as db_owner in "user mapping" of properties
I have faced the same problem and I solved as give db_owner permission too to the Database user.
The general answer is to grant execute permission as explained above. But that doesn't work if the schema owner of SP is different to underlying objects.
Check schema owners by:
select name, USER_NAME(s.principal_id) AS Schema_Owner from sys.schemas s
To change the owner of an schema you can:
ALTER AUTHORIZATION ON SCHEMA::YOUR_SCHEMA TO YOUR_USER;
Examples:
ALTER AUTHORIZATION ON SCHEMA::Claim TO dbo
ALTER AUTHORIZATION ON SCHEMA::datix TO user1;
Finally if within your SP you are truncating a table or changing structure you may want to add WITH EXECUTE AS OWNER in your SP:
ALTER procedure [myProcedure]
WITH EXECUTE AS OWNER
as
truncate table etl.temp
If you only need to grant a single function then (only db admin can do it):
Open Management studio
Find function/procedure you want to grant in Object Eplorer (dbname-Programmability-[Functions/Stored Procedures]-...)
Right click on function or procedure name and open Properties
In Properties select Permissions, add user (or schema) you want and Grant him Execute permission.
I believe this is most secure way how to do it because you only grant to user execution of this function. Nothing else!
I think you have to select the object you want to grant access to, then right-click, and select properties. Select permission on the modal window that will be displayed then click on Search, on the newly revealed window, select browse, select the user you want to grant access and click on ok. it will display for you a list of permission and the grant status, and then you can choose to grant or deny
This shows that you don't have access to perform any action on the specified database table. To enable this, Go to Security -> Schema and check.
you'd better off modifying server roles, which was designed for security privileges. add sysadmin server role to your user. for better security you may have your custom server roles. but this approach will give you what you want for now.
Object Explorer -> Server -> Security -> Logins
Right click on your desired user
Go to Server Roles on left hand side
Make sure sysadmin is checked
Hit OK and restart your SQL server
Good luck

Current transaction ID in an audit trigger

I was looking at storing some form of transaction id from an audit trigger. The solution appeared to be to use sys.dm_tran_current_transaction as in this post SQL Server Triggers - grouping by transactions.
However, I cannot use this because the user account running sql statements will not have the "VIEW SERVER STATE" permission and results in the error:
Msg 297, Level 16, State 1, Line 3
The user does not have permission to perform this action.
Does anyone know of an alternative to this view that will provide a similar transaction id or a way to use "WITH EXECUTE AS" on the trigger to allow selecting from this view.
From my attempts at "WITH EXECUTE AS" it appears that server level permissions are not carried over, which is expected really since it is impersonating a database user.
You can resolve almost any security problem using code signing. Most granular and finely tuned access control, is just a bit on the hard side to understand.
Use EXECUTE AS OWNER on the trigger, create a certificate, sign the trigger, drop the private key (so that noone else can use it to ever sign anything again), export the certificate (public key only), import the certificate in master, create a login derived from the certificate, grant authenticate to this login (in order to extend the database execute as impersonation), then grant view server state to this login. This is bullet proof, perfectly controled priviledge control. If the trigger need to be changed, the signing process (including the cert derived login and grants) have to be done again. From a security point of view, this is desired (you are signing a specific variant of the trigger), from operational point of view is rather a pita, but is manageable.
create table t (i int);
create table audit (transaction_id int);
go
create trigger t_audit_trigger
on t
with execute as owner
after insert, update, delete
as
begin
set nocount on;
insert into audit (transaction_id)
select transaction_id from sys.dm_tran_current_transaction;
if (##ROWCOUNT != 1)
raiserror(N'Failed to audit transaction', 16, 1);
end
go
create certificate t_audit_view_server
encryption by password = 'Password#123'
with subject = N't_audit_view_server'
, start_date = '08/10/2009';
go
add signature to t_audit_trigger
by certificate t_audit_view_server
with password = 'Password#123';
go
alter certificate t_audit_view_server
remove private key;
backup certificate t_audit_view_server
to file = 'c:\temp\t_audit_view_server.cer';
go
use master;
go
create certificate t_audit_view_server
from file = 'c:\temp\t_audit_view_server.cer';
go
create login t_audit_view_server_login
from certificate t_audit_view_server;
go
grant authenticate server to t_audit_view_server_login;
grant view server state to t_audit_view_server_login;
go
From SQL Server 2008, Microsoft introduced sys.dm_exec_requests, which is to deprecate sys.sysprocesses. This view returns the transaction_id, and can be called without granting VIEW SERVER STATE. Like sys.sysprocesses, it returns details for the current process if VIEW SERVER STATE is not granted, and all processes if it is.
Although not directly answering your question, rather than using a custom built auditing framework, in SQL Server 2008 you could make use of the Change Data Capture Technology.
See the following reference from Books Online: http://msdn.microsoft.com/en-us/library/bb522489.aspx
EDIT (Solution, added): Here is a walkthrough of how to create a stored procedure to access the system view, making use of the execute as clause and using impersonation.
USE MASTER;
select * from sys.dm_tran_current_transaction
--Create a login with view server state permissions
CREATE LOGIN ViewServerStateLogin
WITH password = 'Hello123';
CREATE user ViewServerStateLogin;
--Create a login to test the permissions assignment
CREATE LOGIN TestViewServerState
WITH password = 'Hello123';
CREATE user TestViewServerState;
--Test with Login
EXECUTE AS LOGIN = 'TestViewServerState';
--This obviously does not work.
select * from sys.dm_tran_current_transaction
revert;
--Grant view server state permission to the ViewServerStateLogin
GRANT VIEW SERVER state TO ViewServerStateLogin;
--Create a procedure to wrap the call to the system view
CREATE PROCEDURE proc_TestViewServerState
AS
SET NOCOUNT ON;
EXECUTE AS LOGIN='ViewServerStateLogin'
select * from sys.dm_tran_current_transaction
revert;
RETURN(0);
--Assign execute permission to the test accounts
GRANT EXECUTE ON proc_TestViewServerState TO TestViewServerState
--Grant impersonation rights to the test login
GRANT IMPERSONATE ON LOGIN::ViewServerStateLogin TO TestViewServerState
--Test with Procedure
EXECUTE AS LOGIN = 'TestViewServerState';
EXEC proc_TestViewServerState
revert;
Starting with SQL Server 2016, you could use CURRENT_TRANSACTION_ID. According to the docs:
Any user can return the transaction ID of the current session.
Encrypt the stored procedure and don't share the pw for ViewServerStateLogin. Then you get a black box of sufficient density to satisfy the auditors.

How to grant permissions to developers to grant permissions to users?

Is there a way I can give developers permission to grant a user permissions over objects without giving them the option to create users or functions?
I'm trying to limit developers permissions, I recently found out that developers had db_owner permissions in dev and prod environments! So I'm doing my best to stop this madness.
Any good article about this matter?
You can make them members of the "db_securityadmin" database role
As said, if someone could hand out permissions, they could hand out permissions to themselves (or a dummy account). I'm not sure if there is a trick in SQL Server to provide "give user permissions less then me".
The way I would do it is with stored procedures.
Create a stored procedure that gives a specified user a specific right or set of rights (those rights are the ones that regular users are allowed to have). Then give the developers execute access to this stored procedure. In effect you use stored procedures to create a limited version of GRANT, while keeping the full GRANT command to yourself.
If someone can give someone else permissions, he can also give himself the permission to do what he wants. So what is this good for? Probably I don't understand your situation.
Owners of objects can grant permissions on those objects. Provided your developers don't need to grant things like CREATE TABLE rights, you might be able to give them ownership of the objects that you want them to grant permission on.
As Stefan said, giving them grant permissions would effectively give them all permissions, since if they want to do something all they have to do is grant themselves the permissions to do it.
Rather than considering the developers the enemy, though, you may want to consider giving the developers a second user account that's used to administer the database. It's pretty common not to give developers ANY permissions to production, at least on their development account.
Setting permission on objects like stored procedures can be accomplished with "GRANT EXECUTE ON . to ;
However, you may also want to grant security rights at both the login and user level. You will want to determine and grant ONLY the necessary rights for the objects that require access (such as execution). Consider use of the "EXECUTE AS" capability which enables impersonation of another user to validate permissions that are required to execute the code WITHOUT having to grant all of the necessary rights to all of the underlying objects (e.g. tables). The EXECUTE AS can be added to stored procs, functions, triggers, etc.
Add to the code as follows right within the Stored Procedure: CREATE PROCEDURE dbo.MyProcedure WITH EXECUTE AS OWNER
In this case you are impersonating the owner of the module being called. You can also impersonate SELF, OR the user creating or altering the module OR... imperonate CALLER , which will enable to module to take on the permissionsof the current user, OR... impersonate OWNER, which will take on the permission of the owner of the procedure being called OR... impersonate 'user_name', which will impersonate a specific user OR... impersonate 'login_name' with will impersonate a specific login.
MOST of the time, you will only need to grant EXECUTE rights to stored procs and then rights are granted to all objects referenced within the stored proc.
In this way, you DO NO need to give implicit rights (example: to update data or call additional procs). Ownership chaining handles this for you. This is especially helpful for dynamic sql or if you need to create elevated security tasks such as CREATE TABLE. EXECUTE AS is a handy tool to consider for these.
This example may help clarify all of this:
Create a user called NoPrivUser with public access to a database (e.g. dbadb)
USE [master] GO CREATE LOGIN [NoPrivUser] WITH PASSWORD=N'ABC5%', DEFAULT_DATABASE=[dbadb], CHECK_EXPIRATION=ON, CHECK_POLICY=ON GO USE [DBAdb] GO CREATE USER [NoPrivUser] FOR LOGIN [NoPrivUser] GO
NOTE: CREATOR OR OWNER OF THIS PROCEDURE WILL REQUIRE CREATE TABLE RIGHTS within the target database.
use DBAdb go CREATE PROCEDURE dbo.MyProcedure WITH EXECUTE AS OWNER AS IF NOT EXISTS (SELECT * FROM sys.objects WHERE object_id = OBJECT_ID(N'[dbo].MyTable') AND type in (N'U')) CREATE TABLE MyTable (PKid int, column1 char(10)) INSERT INTO MyTable VALUES (1,'ABCDEF')
GO
GRANT EXEC ON dbo.MyProcedure TO NoPrivUser; GO
-- Now log into your database server as NoPrivUser and run the following.
use dbadb go
EXEC dbo.MyProcedure
(1 row(s) affected)
Now try to select from the new table while logged on as NoPrivuser.
You will get the following:
select * from MyTable go
Msg 229, Level 14, State 5, Line 1 The SELECT permission was denied on the object 'MyTable', database 'DBAdb', schema 'dbo'.
That is expected since you only ran the procedure under the security context of Owner while logged on as NoPrivUser.
NoPrivUser as no rights to actually read the table. Just to execute the procedure which creates and inserts the rows.
With the EXECUTE AS clause the stored procedure is run under the context of the object owner. This code successfully creates dbo.MyTable and rows are inserted successfully. In this example, the user "NoPrivUser" has absolutey no granted rights to modify the table, or read or modify any of the data in this table.
It only takes on the rights needed to complete this specific task coded WITHIN the context of this procedure.
This method of creating stored procedures that can perform tasks that require elevated security rights without permanently assigning those rights come be very useful.
I've found that the most dangerous aspect of the db_owner role is that if you issue a deny on a permissions, then the members of the role can grant it back to themselves. I've just started reading about this and I'm testing this
Create role db_ControlDatabase
grant control to db_ControlDatabase
deny backup database to db_ControleDatabase
alter role db_ControlDatabase add member TestUser
So far, I've found that the subject TestUser has permissions without being able to add or remove members of the fixed database roles. You should be able to deny whatever you need at this point like backup certificate, backup master key, etc.
Here is a list of permissions that can be denied or granted:

Error with SQL Server "EXECUTE AS"

I've got the following setup:
There is a SQL Server DB with several tables that have triggers set on them (that collect history data). These triggers are CLR stored procedures with EXECUTE AS 'HistoryUser'. The HistoryUser user is a simple user in the database without a login. It has enough permissions to read from all tables and write to the history table.
When I backup the DB and then restore it to another machine (Virtual Machine in this case, but it does not matter), the triggers don't work anymore. In fact, no impersonation for the user works anymore. Even a simple statement such as this
exec ('select 3') as user='HistoryUser'
produces an error:
Cannot execute as the database principal because the principal "HistoryUser" does not exist, this type of principal cannot be impersonated, or you do not have permission.
I read in MSDN that this can occur if the DB owner is a domain user, but it isn't. And even if I change it to anything else (their recommended solution) this problem remains.
If I create another user without login, I can use it for impersonation just fine. That is, this works just fine:
create user TestUser without login
go
exec ('select 3') as user='TestUser'
I do not want to recreate all those triggers, so is there any way how I can make the existing HistoryUser work?
Detect Orphaned Users, then resolve by linking to a login.
DETECT:
USE <database_name>;
GO;
sp_change_users_login #Action='Report';
GO;
RESOLVE:
The following command relinks the server login account specified by <login_name> with the database user specified by <database_user>:
USE <database_name>;
GO
sp_change_users_login #Action='update_one', #UserNamePattern='<database_user>',
#LoginName='<login_name>';
GO
https://msdn.microsoft.com/en-us/library/ms175475.aspx
What user account does the trigger execute as.
You'll need to grant that user IMPERSONATE priviledges for the User Account HistoryUser.
GRANT IMPERSONATE ON USER:: YourUser TO HistoryUser
More details here
http://msdn.microsoft.com/en-us/library/ms181362.aspx
Problems like this that arise after moving a database from one machine to another usually involve mismatched SID's, although I'm not sure if or how it applies to your case. Try dropping and re-creating the database user, making sure to reinstate its permissions to those tables.
It is an "orphaned user". It wont work. Documentation states this clear.
:-(
Fix "orphaned user" state and it will work again

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