db_reader user with Exec rights on sp which contains INSERT & TRUNCATE - sql

User with db_reader would like to get execute permission on stored procedure that contains INSERT and TRUNCATE statements against existing tables.
Just to see I granted what was requested, but it seems like it doesn't work.
Is such mix of permissions doable?
EDIT: I granted permissions on sp using this:
use [dbName]
GO
GRANT EXECUTE ON [dbo].[spFront_ProcedureName] TO [ABC\serviceAccount]
GO

Granting EXECUTE permission on the Stored Procedure allows the user to call the procedure.
However, depending upon what the procedure does, it may still not do as you expect. Specifically around TRUNCATE, see the info at this link which identifies that additional permission may be needed to use TRUNCATE unless the procedure is carefully crafted.
The specific error message may help identify whether the issue arises from this or if it is from ownership chaining.

Related

Restrict user to Stored Procedures

I need to restrict user access to SELECT, INSERT, UPDATE and DELETE, so that user should manage data only using stored procedures I provide.
So, for instance
SELECT * FROM Table1
should return
The SELECT permission was denied on the object 'Table1'
however, if there is stored procedure SelectTable1 defined as
CREATE PROCEDURE SelectTable1
AS
BEGIN
SELECT * FROM Table1
END
(the real one contains filtering and parameters, so it is not meaningless, like the one above)
user should execute it successfully and get the resultset.
But obviously, I have no success implementing this set of permissions. Can anybody point me to some specific tutorial? MSDN was not very helpful.
Database is SQL Server 2012 and all objects (tables and stored procedures) are in custom schema.
You can do it using GRANT EXEC either on specific procedures or on schemas or on a database.
The following example grants EXECUTE permission on stored procedure
HumanResources.uspUpdateEmployeeHireInfo to an application role called
Recruiting11.
USE AdventureWorks2012;
GRANT EXECUTE ON OBJECT::HumanResources.uspUpdateEmployeeHireInfo
TO Recruiting11;
GO
Thanks to Igor I've got to the right MSDN page, and followed rights links.
However, using ownership chains suggested was too complicated for me, so I used
WITH EXECUTE AS OWNER
on my stored procedures and that works very good. When I log on using restricted user I see only procedures, no tables at all and I can execute procedures, but not even select from tables.
Also, I want to mention this concept is very similar to setuid and thus was familiar to me.
I mark Igors reply as answer, because ownership chains seem to be more generic way, just wanted to share info I found.

SQL Server Execute Impersonation

What is the diffrence between...
execute as user = 'testuser'
AND
execute as login = 'testuser'
I am executing a cross database procedure under these logins and it works with the exececute as login but not the execute as user. It is saying the server principal "testuser" is nt able to access the database "xxx" under the securty context.
When i SELECT SYSTEM_USER after both commands I see that it is set to 'testuser'
execute as login provides impersonation to the entire server, since logins are on a server level. Since users are defined per database, execute as user impersonation applies only to a specific database, which is why you see the error when you cross databases.
The EXECUTE AS can be added to stored procs, functions, triggers, etc.
Example to Execute As:
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...
impersonate CALLER , which will enable to module to take on the permissions of 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.
Setting permission on objects like stored procedures can be accomplished with
GRANT EXECUTE ON <schema>.<procedurename> to <username>;
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).
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 not 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.
Login scope is at the server level while user scope is at the current database level
http://msdn.microsoft.com/en-us/library/ms181362.aspx

How can i set a sql server user to execute stored procredures in readonly mode

I want to set a readony permission to a database user.
This user should have permission to execute stored procedures
But this user should not have permission to update or inser or alter anything in database through these stored procedures or through any methord
can anyone help please
Simply don't grant permission on the stored procs that change data.
Otherwise, you could use triggers on the tables to check, but that's a bit silly compared to using permissions correctly
Note: ownership chaining means that permissions on tables won't be checked, even DENY, so this won't work.
Yes. Set the EXECUTE permission for that user, then they'll only be able to execute the Stored Procedures in your database.
GRANT EXECUTE ON dbo.storedprocedurename TO SQLUSERNAME;
You'll need to set the permissions on a procedure by procedure basis. Give them permission to stored procedures that select, and don't give them permission to the stored procedures that do updates or inserts.The best way is to setup roles, and add the users to the roles.
This is pretty flexible and you can use it to restrict exactly what uses can do. For example, it may actually be okay for them to update a table as long as they do it through a certain stored procedure. To do this you can deny them all permission to that table, but grant them permission to execute the stored proc.
give execute permission on the proc and make sure the user doesn't have write access to the tables used by the proc. Check if he is not member of the db_datawriter roled.
If you want to be 100% sure, add the user to the db_denydatawriter role

SQL SERVER stored procedure problem?

I have created a stored procedure using SQL Server Management studio.
I am able to create it but if I tryto right click on the stored procedure and execute it, I am getting permission denied error# 229.
I have administrator rights. How can I execute this procedure.
if you are really connecting as sa this should not happen, if you are not, could be that your user does not really have all the rights.
It is also difficult to understand the problem without seeing the body of the stored in case you are doing anything special in there.
at this link anyway: http://www.sqlservercentral.com/Forums/Topic463688-146-1.aspx somebody was discussing the same error and there are some SQL commands scrolling down the page where some people claim to have fixed the issue.
Are you sure that you have sufficient permissions?
Error 229 means that you don't.
Your user needs at least EXECUTE permissions for the stored procedure:
Stored Procedure and Permissions - Is EXECUTE enough?
Here's how you can check if you have the permission:
MS SQL Server: Check to see if a user can execute a stored procedure
Verify that you didn't add your user to any of the deny roles, like db_denydatareader.
Use this to add execute privillages to your SQL Login:
GRANT EXECUTE ON SPNAME TO UserName;
GO

Facing an error : table or view does not exist

I am using insert statement and trying to insert data into the database table. I am using stored procedures.
But I am getting this error while doing so.
Message: ORA-00942: table or view does
not exist ORA-06512
I checked if the tables/stored procedures are present or not and everything is in place. Also there is no typo in table names or in sp. If I run the part of SP from query editor it works fine but when I execute the entire SP it throws an error.
I tried the steps provided by Stephen but since I have logged in with the same user/owner when I run Grant command it gives me an error saying 'Cannot Grant/revoke on own'.
One more addition to this. I have a stored procedure SP1 in which I am using a select statement as
Select a from table_name where condition;
When I execute this seperately, it returns me some results. But when I execute sp it gives an error at the same line where it is written.
Can anyone help me out to resolve this issue. I am using SQL +.
Thanks in advance
Vijay
Justin's answer is correct but let me expand a bit.
Everyone who said that the table doesn't exist didn't read your whole post. Since you are able to:
If I run the part of SP from query editor it works fine
Obviously the table is there.
Obviously you have some access to it. Otherwise this wouldn't work when it clearly does.
but when I execute the entire SP it throws an error.
This is because Oracle distinguishes between permissions granted directly and those granted via a role.
Say I do this:
Create Table TABLE_A
Create Role READ_ONLY
Grant Select on TABLE_A to READ_ONLY
Grant READ_ONLY to VIJAY
In a SQL Window/prompt you could query that table without issue. So now you need to create a view
Create VIJAY.VIEW_A as SELECT * FROM TABLE_A
You'll get the error that TABLE_A does exist. Because a view is compiled, like a procedure it runs without any roles. Since it runs without the READ_ONLY role, it's blind to the fact that TABLE_A exists. Now what I need to do is
Grant Select on TABLE_A to VIJAY.
Now that you have a direct permission, you can compile a view or procedure/package that uses that table.
Does the table exist in the schema where the stored procedure exists? If not, the simplest explanation is that the owner of your procedure has been granted access to the table via a role not via a direct grant. A definer's rights stored procedure needs to have direct access to the objects it accesses. A quick way to test this is to disable roles for the session, i.e.
SQL> set role none;
SQL> <<execute your query>>
If that generates the error, the problem is the lack of a direct grant.
In Oracle you can choose if the stored procedure is executed with the rights of the invoker or the definer: http://download.oracle.com/docs/cd/E11882_01/appdev.112/e17126/subprograms.htm#i18574
Check if the AUTHID property of the stored procedure is correct and if the resulting user has appropriate permissions.
Well, put very simply, the table that you are trying to insert data into does not exist in the database you are connected to. You need to check both those things (i.e. what are you connected to, and is the table there and accessible for the user context you are using).
As Joe Stefanelli said .. there are a lot of possibilities for the error being shown here.
Check whether:
You are connecting to the correct Oracle Instance.
You have permissions to query or perform processing on table that you are referencing in your query.
There is a difference between ordinary select statements and procedures. Procedures in oracle do not respect the roles assigned to a user; rather the permission needs to be explicitly granted to the user. For more information read the following linkORA-00942