Grant EXECUTE permission Doesn't GRANT Select permission on tables - sql-server

I have a store procedure that have several selects for checking and balances in our order process, long story short, this store procedure reads (SELECT) about 20 tables with are spread in 3 databases.
CREATE USER [stageUsrOrder] FOR LOGIN [domain\[my user]]
GO
CREATE ROLE OrderSpecRole AUTHORIZATION [stageUsrOrder]
GO
GRANT EXECUTE on [orders].[ValidateOrderById] TO pmdSchedulerRole
GO
I thought that this statements would give me read access to all the tables inside the store procedure.
I have try
GRANT EXECUTE on [AVIS].[spReportValidationByLAN] TO pmdSchedulerRole WITH GRANT OPTION
GO
But it didn't work.
So, How do I grant execute access to the store procedure and SELECT to all the tables inside?

You don't. One of the value propositions of stored procedures is that you can restrict access to certain patterns. For example, if you want people to only search by ID, you give then a stored procedure that takes ID as a parameter.
But if you want to give them arbitrary select access to the underlying tables, you have to do that explicitly.

Related

Stored procedure to act differently based on user role

I'm trying to figure out if there is a way to achieve the converse of this:
can a SQL Server stored proc execute with higher permission than its caller?
I want to create a stored procedure which does one thing if the user is in a role, but a fallback option if they're not.
My first attempt tried to query the current user's roles, based on this:
How to query current user's roles
I tried to query what role a user was in, and decide what to do based on that. But if you set "mydomain\Domain Users" to a role (for example), users who belong to Domain Users aren't listed in the sys.database_role_members view. So users who were supposed to have permissions don't.
From here https://msdn.microsoft.com/en-us/library/ee677633.aspx
IS_ROLEMEMBER always returns 0 when a Windows group is used as the database
principal argument, and this Windows group is a member of another Windows
group which is, in turn, a member of the specified database role.
My next attempt works like this. Create a stored procedure with the actual permissions, and then a wrapper around it which calls the with lower permissions, and if that fails, perform the fallback action:
CREATE PROCEDURE [internal_myproc]
AS
BEGIN
-- do something here
END
GO
GRANT EXECUTE ON [internal_myproc] TO [Role1] AS [dbo]
GO
CREATE PROCEDURE [myproc]
AS
BEGIN
BEGIN TRY
EXEC [internal_myproc]
END TRY
BEGIN CATCH
-- perform fallback action
END CATCH
END
GO
GRANT EXECUTE ON [internal_myproc] TO [Role1] AS [dbo]
GO
GRANT EXECUTE ON [internal_myproc] TO [Role2] AS [dbo]
GO
GRANT EXECUTE ON [internal_myproc] TO [Role3] AS [dbo]
GO
The problem with this is that [Role1] and [Role2] both succeed in executing [internal_myproc] via [myproc]. If you take the code out of the stored procedure, it behaves the way it should, but because it's hidden inside a stored procedure, it gets implicit permissions to execute other stored procedures. I've experimented with "WITH EXECUTE AS" stuff, but it doesn't seem to change anything.
I also tried "IF HAS_PERMS_BY_NAME('internal_myproc', 'OBJECT', 'EXECUTE') = 1", suggested here MS SQL Server: Check to see if a user can execute a stored procedure , but that seems to not work in certain situations I haven't understood yet.
Is there a way to NOT grant those implicit permissions, to do a permission check inside a stored procedure? Or something equivalent?

Grant all tables (except 1) Read permission on a Role while not knowing which tables there are every day

Every day in our datawarehouse (that will be dynamically changing) the tables are dropped and rebuilt. Also is it possible that some developer in our organisation will create more tables in that database.
Because of that I can not give permissions to the database that are persistent.
Question:
I want to make some kind of a job that runs every day, that lists all the table names (that are existing at that time) in a database like 'Select * FROM sys.tables'
Then I want the tables names as an input value to a script that runs trough all table names and places them in a script like :
GRANT SELECT TO [Tablename1] TO [ROLE_READALLTABLES Except 1 table],
GRANT SELECT TO [Tablenaam2] TO [ROLE_READALLTABLES Except 1 table]
and so go on in a loop until all existing tables are readable.
So all tables (except 1 table ) in the entire database should get the GRANT SELECT permission.
I have looked around all the related answers, but I cannot seem to get a good idea how to get this to work.
I hope someone can help me with this.
UPDATE
I use Microsoft SQL Server 2014, and I work through SQL Management Studio 2014
UPDATE 2 :
There is one exception. This table has schema [dbo]. like all other tables
You can use the db_datareader role to grant access to all tables generally, then a specific role with a DENY rule to exclude access to the one table that's the exception.
The steps would be roughly like this:
1) Create your "Read all except 1 role":
CREATE ROLE [ROLE_READALLEXCEPT1]
2) Create your "deny" role like so:
CREATE ROLE [ROLE_DENY]
GO
DENY SELECT, INSERT, UPDATE, DELETE ON myTable TO [ROLE_DENY]
GO
3) Then add your "except 1" role to it:
EXEC sp_addrolemember #rolename = 'ROLE_DENY', #membername = 'ROLE_READALLEXCEPT1'
4) Add your role to db_datareader:
EXEC sp_addrolemember #rolename = 'db_datareader', #membername = 'ROLE_READALLEXCEPT1'
The deny role should override db_datareader, and the net effect is that your role now has access to all tables (including new ones) except for those explicitly denied.
You can then add your users to "ROLE_READALLEXCEPT1" and they will have access to everything except the one exception table.
there is no information about the excluded table so i assume is always the same.I also assume that all the other tables are on the schema dbo; this is not a relevant constraint or limitation because the logic can be easily applied to more than one schema.
the easiest solution is granting permission at the schema level. move the single table on a separate schema with restricted permissions and grant full read on the whole schema where the user tables reside:
GRANT SELECT ON SCHEMA::dbo TO [relevant role/user];
now the developers can create all the table they feel like on the schema dbo and the permission are inherited by the schema.
should you need to grant access to more than one schema the permission are easily applied once and then every new table will get proper permission.
the huge pro of this solution is that it is fire and forget: once in place there is no maintenance, no jobs, no script to run daily/weekly/whatever.
this advantage is to be evaluated and weighted against the move of the excluded table (or the other way round: move the user tables): maybe is used by just a couple of internal applications so it is a quick patch or is used by a whole bunch of services accessible worldwide instead and that would be a nightmare.

sql server default procedure permissions

I want to know what are the default permissions for sql server stored procedures.
For example, I created a user in database but no role or no permissions granted except execute permission like:
GRANT EXECUTE ON SCHEMA :: [dbo] TO [newUser]
later on me (as a sa login) created a stored procedure that makes just a select from a table like:
CREATE PROCEDURE dbo.selectX AS
BEGIN
SELECT ID, NAME FROM MyTable
END
and my user [newUser] can execute and see the result of select statement like:
EXEC dbo.selectX
up until now, I can assume that stored procedures have default permissions that my user don't have.
I tried other dmls like UPDATE, INSERT, DELETE and user managed to execute procedures successfully.
But! when I created a proceure with ddl as create table .. such as:
CREATE PROCEDURE dbo.crtNT AS
BEGIN
CREATE TABLE del(id int) --for test
END
and when the newUser executes this procedure error occurs like:
CREATE TABLE permission denied in database 'MyDb'
And here is my question: By default, do stored procedures have permission with DML(select, insert, update vs.) but not with DDL(create, drop table vs.)? Because I didn't see any explanation about this situation in Books Online or anywhere else.
Any comments will be welcomed.
You are correct in your assumption that DDL statements are treated differently.
The procedures with DML statements work through the mechanism of Ownership Chaining however as this quote from the EXECUTE AS documentation states
Remember that ownership chaining applies only to DML statements.

Stored Procedure and Permissions - Is EXECUTE enough?

I have a SQL Server 2008 database where all access to the underlying tables is done through stored procedures. Some stored procedures simply SELECT records from the tables while others UPDATE, INSERT, and DELETE.
If a stored procedure UPDATES a table does the user executing the stored procedure also need UPDATE permissions to the affected tables or is the fact that they have EXECUTE permissions to the stored procedure enough?
Basically I am wondering if giving the user EXECUTE permissions to the stored procedures is enough or do I need to give them SELECT, UPDATE, DELETE, and INSERT permissions to the tables in order for the stored procedures to work. Thank you.
[EDIT] In most of my stored procedures it does indeed appear that EXECUTE is enough. However, I did find that in stored procedures where "Execute sp_Executesql" was used that EXECUTE was not enough. The tables involved needed to have permissions for the actions being performed within "sp_Executesql".
Permissions on tables are not checked (including DENY) if tables and proc have the same owner. They can be in different schemas too as long as the schemas have the same owner.
See Ownership chaining on MSDN
Edit, from a comment from a deleted answer.
The context is always the current login unless EXECUTE AS as been used: only referenced object DML permissions are not checked. Try OBJECT_ID(referencedtable) in a stored proc where no rights are assigned to referencedtable. It gives NULL. If executed by the owner of the stored proc then it would give a value because owener has rights on referencedtable
Execute permissions on the stored procedure is sufficient.
CREATE TABLE dbo.Temp(n int)
GO
DENY INSERT ON dbo.Temp TO <your role>
GO
CREATE PROCEDURE dbo.SPTemp(#Int int)
AS
INSERT dbo.Temp
SELECT #Int
GO
GRANT EXEC ON dbo.SPTemp TO <your role>
GO
Then the (non-db_owner) user will have the following rights:
EXEC dbo.SPTemp 10
GO
INSERT dbo.Temp --INSERT permission was denied on the object 'Temp'
SELECT 10
However, if there is dynamic SQL inside dbo.SPTemp that attempts to insert into dbo.Temp then that will fail. In this case direct permission on the table will need to be granted.
Maybe you can use
"with execute as owner"
when you create the stored procedure, such as below:
create procedure XXX
with execute as owner
as
begin
...
end
go
Then you only need to grant the user the EXECUTE permission for the stored procedure XXX.
Execute permission on a stored procedure that does an insert, update, or delete is sufficient. You do not need to grant those permissions at the table level. In fact, I would discourage that approach. Using a stored procedure gives you more control over how the change occurs. For instance, you may wish to do some checking prior to allowing the update. Using a stored procedure can also help prevent major accidents--like deleting all the rows in the table because someone forgot the WHERE clause!
THANK YOU SO MUCH! I had a similar problem. This lead me to the answer.
I was attempting to trunctate a table in a stored procedure that called other stored procedures that were nested in IF statements.
My error was
The server principal "domain\my_id" is not able to access the database "2nd_DB" under the current security context.
I had given the calling stored procedure rights to do the truncate (EXECUTE AS SELF), which then caused a problem because SELF didn't have rights to the 2nd DB. Our solution was to move the truncate to another SP, include the EXECUTE AS SELF. We now call the truncate SP, execute our data processing, make logic determination, and call the appropriate 3rd SP.

Multi-Schema Privileges for a Table Trigger in an Oracle Database

I'm trying to write a table trigger which queries another table that is outside the schema where the trigger will reside. Is this possible? It seems like I have no problem querying tables in my schema but I get:
Error: ORA-00942: table or view does not exist
when trying trying to query tables outside my schema.
EDIT
My apologies for not providing as much information as possible the first time around. I was under the impression this question was more simple.
I'm trying create a trigger on a table that changes some fields on a newly inserted row based on the existence of some data that may or may not be in a table that is in another schema.
The user account that I'm using to create the trigger does have the permissions to run the queries independently. In fact, I've had my trigger print the query I'm trying to run and was able to run it on it's own successfully.
I should also note that I'm building the query dynamically by using the EXECUTE IMMEDIATE statement. Here's an example:
CREATE OR REPLACE TRIGGER MAIN_SCHEMA.EVENTS
BEFORE INSERT
ON MAIN_SCHEMA.EVENTS REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
DECLARE
rtn_count NUMBER := 0;
table_name VARCHAR2(17) := :NEW.SOME_FIELD;
key_field VARCHAR2(20) := :NEW.ANOTHER_FIELD;
BEGIN
CASE
WHEN (key_field = 'condition_a') THEN
EXECUTE IMMEDIATE 'select count(*) from OTHER_SCHEMA_A.'||table_name||' where KEY_FIELD='''||key_field||'''' INTO rtn_count;
WHEN (key_field = 'condition_b') THEN
EXECUTE IMMEDIATE 'select count(*) from OTHER_SCHEMA_B.'||table_name||' where KEY_FIELD='''||key_field||'''' INTO rtn_count;
WHEN (key_field = 'condition_c') THEN
EXECUTE IMMEDIATE 'select count(*) from OTHER_SCHEMA_C.'||table_name||' where KEY_FIELD='''||key_field||'''' INTO rtn_count;
END CASE;
IF (rtn_count > 0) THEN
-- change some fields that are to be inserted
END IF;
END;
The trigger seams to fail on the EXECUTE IMMEDIATE with the previously mentioned error.
EDIT
I have done some more research and I can offer more clarification.
The user account I'm using to create this trigger is not MAIN_SCHEMA or any one of the OTHER_SCHEMA_Xs. The account I'm using (ME) is given privileges to the involved tables via the schema users themselves. For example (USER_TAB_PRIVS):
GRANTOR GRANTEE TABLE_SCHEMA TABLE_NAME PRIVILEGE GRANTABLE HIERARCHY
MAIN_SCHEMA ME MAIN_SCHEMA EVENTS DELETE NO NO
MAIN_SCHEMA ME MAIN_SCHEMA EVENTS INSERT NO NO
MAIN_SCHEMA ME MAIN_SCHEMA EVENTS SELECT NO NO
MAIN_SCHEMA ME MAIN_SCHEMA EVENTS UPDATE NO NO
OTHER_SCHEMA_X ME OTHER_SCHEMA_X TARGET_TBL SELECT NO NO
And I have the following system privileges (USER_SYS_PRIVS):
USERNAME PRIVILEGE ADMIN_OPTION
ME ALTER ANY TRIGGER NO
ME CREATE ANY TRIGGER NO
ME UNLIMITED TABLESPACE NO
And this is what I found in the Oracle documentation:
To create a trigger in another user's
schema, or to reference a table in
another schema from a trigger in your
schema, you must have the CREATE ANY
TRIGGER system privilege. With this
privilege, the trigger can be created
in any schema and can be associated
with any user's table. In addition,
the user creating the trigger must
also have EXECUTE privilege on the
referenced procedures, functions, or
packages.
Here: Oracle Doc
So it looks to me like this should work, but I'm not sure about the "EXECUTE privilege" it's referring to in the doc.
What you are experiencing is a feature of Oracle's security model. The entire point of using schemas is to control access to the data. The tables in my schema are mine, you cannot even see them until I grant you privileges on them.
The syntax is quite simple: the owner schema issues
grant select, insert on my_table to you
/
Alternatively an account with the GRANT ANY privilege (such as a DBA) can pass privileges on any user's objects.
grant select, insert on apc.my_table to you
/
The grantee can be either a user or a role. However, note that we can only build program units - stored procedures, views, triggers - using privileges which have been granted directly through to our user.
So, if you get the other schema owner to grant you the necessary privileges you will be able to build your trigger.
edit
When referencing an object in another schema we need to qualify the object with the schema name ....
insert into apc.whatever_table values ...
or else we need to create a synonym for it
create synonym whatever for apc.whatever_table;
I feel someone should add the obvious - the other schema's table must be qualified with the schema name or a private/public synonym is needed. I wonder if the original problem was merely a name resolution issue. If not, APC's answer is a good explanation of the Oracle security model.
You should execute this for every table and schema involved:
grant select on OTHER_SCHEMA_%.table_name to MAIN_SCHEMA;

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