Question: As a DBA/BI Developer, should we install SSMS on the PCs of power-users of business data? What are the risks with this approach?
Context: I love SSMS. It's ergonomically designed and enables not just the exploration and management of the SQL Server, but also the data within it (e.g. select/edit rows)
Our business users are not interested in the server, just the data. Some of them grasp the data models but are limited in what they can do with the data by the production system interfaces. We are initiating BI projects to improve data access in the medium-term.
In the short-term, a quick install of SSMS 2014, a Windows Authenticated Login and User with minimum required permissions, and some training would appear to satisfy some of our data management requirements. Some of the users can already write basic SQL.
You can do it but you cannot grant the users anything but very limited permissions. Do not grant the dbo privileges or even worse SA. Take the time to really lock down what they can do (except for select) and be very careful about what SQL server groups you put them in (if any).
Even on selects you should think about (i.e. don't do it) putting them in the db_datareader group which will allow them to read any table in the database. You can revoke permissions but you may forget to revoke read from at view they shouldn't see. I would grant them limited permissions and as they complain add, if appropriate, more permissions.
Related
The Problem
Good Morning! I work on an application team that supports a few applications which utilize SQL Server for data storage. Recently, our Database Support team decided that SQL Authentication was no longer permissible (for security and logging reasons) and so my team was forced to convert all connections to Windows Authentication including several dedicated Service IDs that our applications had been utilizing for data retrieval.
First, let me say there most certainly are advantages to moving to Windows Authentication, I am not trying to dispute that. But this change has raised a huge problem for us... by switching our Service IDs to Windows Authentication we have now opened up our back-end databases to every internal business user with front-end application access.
MS Access is pushed out to every user desktop and a few superusers even have access to SSMS. At this point we are relying entirely on user ignorance to prevent internal users from accessing the back-end database directly. And given that certain roles have elevated DML rights, this presents a possibility for some nasty data consequences.
This new enterprise standard has left my team stuck between a rock and a hard place at this point so we looking for any database, account or architecture solution that would allow us to restrict user access to front-end only.
Questions
Has anyone else run into this problem? Is there an architectural solution we are missing that would allow us to eliminate SQL Authentication without exposing our databases?
Does anyone know of a way to restrict access to a SQL Server database to only certain connection methods? I'm wondering if there is a way to designate a specific ID (or role) as only allowing a connection through a front end (and eliminate ODBC connections entirely).
Does anyone have any clever workarounds?
-------------EDIT---------------
A couple people brought up a good point about role access so I wanted to clarify our former and current solution... Previously, all role access was managed on the front-end and data retrieval was handled entirely by private system SQL Authenticated IDs to which end users had no visibility.
When we were forced to eliminate these SQL Auth IDs, we created a similar role-based setup on the back-end database as existed on the front end. Active Directory Groups were created to house different groups of users and these groups were assigned specific role privileges in the database. So currently access is limited by role as much as feasible.
The problem is that even the lowest privileged roles have INSERT, UPDATE and DELETE access to some tables (access which is normally controlled through code). So while we were able to mitigate risk somewhat by utilizing database roles, we still have areas where a user can bypass front end protections by logging directly into the database.
EDIT: Question clarification makes this answer obsolete, but leaving it for reference since some comments discuss it.
Assuming you mean that you have to (based on your architecture) allow access to the DB to each windows user account, one options is to use database roles.
You disable public access to your database, then define a set of database roles, depending on your use cases. Each role is granted permissions such that members of that role are able to manipulate the data they need and or work with the objects they need. Users are then mapped into the roles they require. When connecting to your database, the user will be granted permissions according to the roles they are members of.
For example, we have a role in one of our databases named MyAppUser (our name is actually related to the app which uses the db), which is designed for end users to read and insert data only. These can be created simply as follows:
CREATE ROLE [MyAppUser]
The role is granted just the permissions it to the relevant schemas or tables (assume all our "public" tables are in dbo schema for now).
GRANT SELECT ON SCHEMA::[dbo] TO [MyAppUser]
GRANT INSERT ON SCHEMA::[dbo] TO [MyAppUser]
GRANT DELETE ON SCHEMA::[dbo] TO [MyAppUser]
Each user who should have this public read-write access is then mapped into the relevant role.
ALTER ROLE [MyAppUser] ADD MEMBER [UserName]
This separates users and roles / permissions within your database and allows you to have a single point of entry to control who has access to what in your databases.
By having the "View Definition" permission denied by default (to end users), they won't be able to "explore" the database / view table definitions etc using access, or even SSMS.
NB: SSMS provides wizards for managing and viewing permissions and memberships which are very handy for getting things initially setup / tested / fiddled around with.
On a certain site there is report system. The system is based on running SQL queries that are stored in the database. Those queries are executed through a db_datareader user. Generally those queries are written by the site admin. Assuming an attacker managed to get access to site admin account and can add any query he likes to the report system, are there any dangerous ones that he can execute as a db_datareader user? (By dangerous I mean things that can help the attacker gain control of the server or gain SA access to database.)
If there are such queries are there steps I can take to prevent the report db user (the one with db_datareader role) from executing them?
Users with the db_datareader role can only issue SELECT queries against tables and views in the database, and no other kinds of queries.
So while a malicious user might be able to view some data that you don't want him to see, he can not do anything that is dangerous by your definition.
I've searched high and low for how to do this. Let me give some background so we can avoid repeating the same old stuff.
At my company we sometimes receive hundreds of databases a month from external sources (i.e., we don't know what database users exist on these db's and never will). I would like to have my analysts attach these databases -- using SSMS or another graphical tool -- WITHOUT giving them the sysadmin server role.
According to my research, the server roles dbcreator (and bulkadmin ???) are needed for attaching databases; however it appears that SSMS won't even show the Attach dialog box for users who don't have the sysadmin server role.
Although I'd prefer a set of permissions which allow users without sysadmin role to use SSMS or other GUI tools to attach / detach databases, I'd be interested in ANY way to do this.
Any ideas? Thanks.
What's a good way to manage and maintain SQL Server logins, server roles, and individual access rights across multiple databases that exist in multiple environments? What are your best practices?
Some info about my situation:
SQL Server 2005
We have N amount of "client" databases with identical schemas (in theory, at least)
We have a central "admin" database that references each client database and can hold configuration values
This "admin/client" pattern is duplicated across multiple environments (dev/qa/stage/prod)
Some users, like testers, need different rights based on evironment
We frequently have to pull client db backups from one environment to restore on another for development or testing purposes
We keep our stored procedures and scripts in source control and deploy in a build cycle
Right now my organization is chaotic and we don't follow good security practices. We have no formal DBA. However, if we got any more complex it would be a constant hassle to maintain it all the time. I could see migrating to a new server or recovering from disaster being extremely time consuming if we where to attempt configuring it directly through the management studio IDE.
First, to make restoring a database to a different server easier, make sure that your logins all have the same SID on all of your servers by using the sp_help_revlogin stored procedure from Microsoft to script the login on the first server you create it on and then use the script to create the login on your other servers. This keeps the database user mapped to the login correctly when you restore the database.
Having different permissions at the database level depending on the environment is going to be a hassle to a point no matter how you role this out. I have a stored procedure in master that gets called on my Dev Server as a part of my restore process that performs the additional GRANT's on the database to give the developers access to make changes. That's the best I have been able to come up with to solve similar problems.
A way to make the rights easier would be to create rolls in the database called Dev, QA, Test, Prod and grant the correct rights to those roles. Then as you restore the databases to each environment just drop the developers in the correct role.
We use active directory groups and enforce windows authenticated logins. From within SQL Server we can then define access based on the AD group the user is in by creating a single SQL Server login per AD group. Not sure if this is any better or worse than DB roles, but it means the roles are managed outside each database.
Propagating access to databases is then either a manual operation or a short SQL script to ensure the logins in the database point to a valid SQL Server login (which in turn is an AD group).
Generally this works well for the general case. We can use DB roles then to assign the builtin roles (e.g, db_datareader) to each AD group
Rarely someone needs some specific access to a database outside this model. We either end up opening it up to the group as a whole if it's not going to be invasive or critical or we'll end up creating a per-user account that has to be managed separately. We endevour to keep these to an absolute minimum, and clean them up every now and then so they're not abused/forgotten about.
We have some corporate intranet users using a WinForms app to work on a system with SQL server behind. Integrated Security is setup, allowing all users update and delete permissions, where application security limits how and where table updates take place.
However, some users are power users with SQL query tools at their disposal, and access the DB directly for building reports. However, with integrated security, they have default update rights on tables where they should not have, as the application apply rules to the updates.
Is this an example of where it's more appropriate providing the app with a central SQL authenticated login, whilst users get read only rights for integrated security?
As Jon mentioned stored procedures would give you the protection over direct table modifications. There are other options too. You can use SQL Server's "Application Role" (via sp_setapprole proc). This enables you to continue to use a separate ID for everyone but only at application connection time (through the front-end) are the user's rights elevated.
A major downside to using a shared ID is you lose track of who is submitting SQL to the server though if they're all internal you can get to the machine name.
Something else is concerning though. It sounds as if your users can connect to the database and run queries at will. You run a major risk of downtime in the application due to user behavior in the directly connected SQL sessions. If you can pull it off you may want to try to have a reporting database created that is updated at intervals that your business can tolerate, i.e., daily. HTH
I presume from the way that you've worded your question that your app executes sql statements directly. If you could refactor it so that it executes stored procedures, you could grant exec rights on the procedures and deny direct updating of the tables. This might not be possible though, depending on what your app does.
sql authentication is one option. Stored procedures are another. However, building more granular roles for assigning just the appropriate permissions to just the appropriate user types is where you should really be looking.
Additionally, I would really avoid giving these users direct access to the DB at all. Security reasons aside, it doesn't take much for a user who isn't proficient in SQL to accidentally execute a query that will swamp your database server and create an effective denial of service. Even pros can do this accidentally from time to time.
Instead, give them access to a reporting services or analysis services type solution, or use replication to give them access to a clone of the data. This way your production system is protected.
Personally I would do all application data access through stored procedures. I would set Integrated security to only allow users to run the SP's and not manipulate the data directly.
Advanced access can be given to DB admins to manipulate the data directly when needed.
Group based permissions will provide you with much more flexibility for access rights, and less administrative burden when controlling these with integrated security.