I want to create a linked server in one sql server to another using the sp_addlinkedserver procedure. When i access the remote server I would like it to logon as me (i.e. using my windows account). How do I do this?
You can do this with the sp_addlinkedsrvlogin procedure:
EXEC master.dbo.sp_addlinkedsrvlogin
#rmtsrvname=N'<your linked server name>',
#useself=N'True',
#locallogin=NULL,
#rmtuser=NULL,
#rmtpassword=NULL
This assumes you log in to the server on which the link was created using Windows authentication.
Following on from Ed Harper above:
You need to set "Security Account Delegation" for the SQL service account to enable it to pass through your login token.
Edit:
This is not a SQL problem. Delegation/pass through authentication is a Windows/AD feature.
It's also used to enable an intranet web site to use the end user windows login to authenticate onto the SQL box where (of course) the web server is a separate box.
In this scenario, you configure the web server for delegation.
In the OP's scenario, we are enabling the 1st SQL box to delegate credentials onto the 2nd box.
Edit2:
The other thread explains this too.
Finally, nothing to do with SQL logins.
This can be maddening to set up. Check this related question:
https://stackoverflow.com/questions/33153/sql-server-to-sql-server-linked-server-setup
With Sql Server 2005 on a 2K3 domain, the most secure way to set up a linked server, unfortunately, is probably to use an old fashioned Sql Login. You have to make a lot of what I consider risky changes to your domain security settings to get it to work with a domain account.
Use SQL Management Studio to see the properties for the linked server.
There you will find your logon information
Related
I am venturing into SQL injection over the past few days. I am able to leverage a SQL injection vulnerability to bypass login and ping back to my attacking machine from the same injection point using exec xp_cmdshell
My question is how can I get some remote reverse shell kind of connection back to my host machine. What all can I achieve using the xp_cmdshell with whatever default tools installed on the vulnerable server?
Any help regarding xp_cmdshell perhaps any links to the resources would be really helpful.
Thanks
Here's a couple of things that might help;
Its probably worth pointing out that whatever you are using to connect to SQL Server will need to be given the sysadmin server role to use the xp_cmdshell procedure. Also the functionality is not enabled by default. An existing sysadmin would have to change the advanced configuration options first to allow xp_cmdshell use.
Here's how to do that: https://msdn.microsoft.com/en-us/library/ms190693.aspx
Next any commands you pass to the OS will execute as the SQL Server database engine service account, not the SQL user, which may have restricted access. Plus even if the service account is a local admin in Windows you won't be able to force cmd style permissions elevation from SQL Server alone. You'll need the service account password too, assuming this is a domain service account.
Here's the MSDN article about the procedure:
https://msdn.microsoft.com/en-us/library/ms175046.aspx
From server1, I've created a connection to a remote server (server2) with the Linked Server facilities. Both servers are on the same domain. When I log to server1 I can successfully execute my stored procedures from SQL Server Management Studio but when I execute my stored procedures from my browser application I get the following error on server 2.
Error: 18456, Severity: 14, State: 58.
Login failed for user 'sa'. An attempt to login using SQL authentication failed.
Server is configured for Windows authentication only.
I've searched the Internet and Stackoverflow for solutions but I'm not sure what's the best way to solve this issue. I'm sure it involves adding/changing database security settings but I'm unsure where to make these changes.
Thanks in advance.
Right-click the server in Enterprise Manager, select properties, goto Security, and change to SQL Server and Windows Authentication mode.
Mixed mode is required if you want to use sa or any other sql-account for authentication. However i believe that the recommended way is to keep the server at Windows authentication mode, and use domain accounts for authentication. The sa-account is the quick and dirty way.
If you have the exact same security setup on both servers, the link between them should work if you select "Be made using the login's current security context" in the linked server properties. That way, the account will be "inherited" in the connection to the linked server.
Check under Security - Logins on each of the server so that the same account is added to both servers. Also check the properties of both entries, under Server Roles you can try to add the sysadmin-role to make sure the accounts will have access to all databases on the server. You should however limit this access in live environments :)
Our custom SharePoint site uses a standard connection string (in web.config) to a remote sql server using a sql server authentication. I need to know if it is possible to change this connection to use a SharePoint service account instead of a sql server account. If so, how do specify the service account in the connection string and how do you create a login and user for an sp service account when that user does not exist on the sql server machine and nor is it available on Active Directory.
Update:
I think I need to use integrated security in the connection string and run db calls within SPSecurity.RunWithElevatedPrivileges block. If i use this as a delegate, what sp account will the code be executed under and how do i assign a sql server login to a sharepoint account on a remote machine. Any links to sample code or articles explaining this process would be helpful.
Thanks.
From the SQL Server side, you should create a domain account for Sharepoint in AD. Then you log in to SQL Server via Management Studio (SQL2005 or later), on the left hand side click on security tab, and add a new login - you'll enter the domain Sharepoint service account, and give it the relevant permissions to the databases it needs to access.
For the Sharepoint side, you probably can edit web.config but there must be a Sharepoint admin tool to take care of this properly.
This is rather embarrassing, but I accidentally deleted my Windows account from the list of SQL Server 2008 users and I cannot for the life of me figure out how to re-add myself now that I don't have login privileges.
The server is running on my machine and the only other Windows users with access are IUSR, NETWORK SERVICE and SYSTEM. Is there anything I can do short of re-installing?
I also recently deleted my windows account from my local development 2008 server. I was able to use SQL server's Single User Mode to recreate my login and add it to the sysadmin role. It took just a few minutes, and I didn't have to admit my terrible error to anyone.
From MSDN:
Starting SQL Server in single-user mode enables any member of the
computer's local Administrators group to connect to the instance of SQL
Server as a member of the sysadmin fixed server role.
Here's how I reinstated myself:
Exit out of SSMS
Stop any SQL related services. I had to stop Reporting Services. Other SQL services such as SQL Agent will also use up your one, valuable connection.
Stop the SQL service
Start the SQL service with the extra parameter -m. This will put the SQL into Single User Mode. This means that SQL will only accept one connection.
Use sqlcmd to connect to your server with the -E trusted connection option. SQL will accept you into the sysadmin role if you're a local administrator.
In the interactive session, create your login and add to the sysadmins role.
USE master
GO
CREATE LOGIN [domain\username] FROM WINDOWS WITH DEFAULT_DATABASE=[Master]
GO
EXEC sp_addsrvrolemember #loginame=N'domain\username', #rolename=N'sysadmin'
GO
Stop the SQL service, remove the -m parameter and restart the service. You should now be able to go back into SSMS and continue using the server normally.
If you get the message:
Login failed for user 'domain\username'. Reason: Server is in single user
mode. Only one administrator can connect at this time.
Then there is something using your single connection. You'll need to find that service or connection and stop it before you can log in. Check SQL Agent, SQL Reporting Services, SQL Analysis Services etc.
Luckily, this wasn't too hard to fix (not that it should have been hard...)!
This blog post explains the steps for starting SQL Server in Single User Mode, which (for some reason) allowed me to login as my Windows administrator account, add the account to the user list (with CREATE LOGIN), enable the SA user and set its password to something I actually knew, and finally login as SA and give the Windows account sysadmin privileges.
Edit 07/05/13: Try this link instead.
Often SQL Server is installed so that any any local administrator is a SQL Server sysadmin.
If this is your case you can run Management Studio as administrator and then add any other windows user as a login in the Security section.
This solution worked for me.
I have a remote database I need to create a linked server to. The problem is it's been set up with my group's functional account an not my own. The only way I can think of doing this is logging out of my personal work account and then back in with out functional account and then set up the link that way, but that is impractical.
So my question is, is there any possible way to set up a linked server using different active directory credentials on a SQL Server 2005 server?\
EDIT: Bascially I am logged in as AD_MAIN\OhioDude but I need to authenticate to the remote server using AD_MAIM\DeptGroup
You can change the properties of the linked server so it uses an alternate set of credentials. From SSMS if you right-click on the linked server and go to Properties -> Security, you can change how the authentication is done for the remote server. I don't know if you can specify a Windows-based login for the remote security context, but it's worth a try.