Auditing Login Attempts

Cedric Charlier shows how to use server audits to track failed and successful logins (and logouts):

The core issue is that we have many users and logins on our databases and we have huge doubt their respective needs. The root cause is identified: sometimes, for a short period of time, we’re making exceptions to our own rules and let a few other friend projects access to our DEV database. On some other cases, we’re connecting our own solution in DEV environnement to the QA environnement of another solution. Why … planning, data quality issue, … we’ve valid reasons to do it … but these exceptions should be removed as soon as possible. And you know what? People forget. Nowadays, on our largest solution, we have 20 users but only 7 of them are expected and documented … other should be removed. But before executing this cleanup, we’d like to be sure that these users are not effectively used by other solutions. If it’s the case, we’ll need to update first the configuration of the corresponding solution.

Click through for a few scripts to show how to set this up as well as how to query the audit log.

Table And Column Deny Precedence

Shane O’Neill has a bit of fun:

Paranoia Kicks In:

He can’t have updated it…right?

I mean, he doesn’t have db_datawriter permission; I’ve denied him update permission on my table. I’m safe!…right?

This is a fun article which highlights just how hard getting correct, granular permissions can be.

Securing A Data Driven Application

K Brian Kelley has started a series on securing applications which connect to SQL Server:

In conjunction with the webinar I gave last month for MSSQLTips, I’ve started an article series on application database security design.

Read Part 1 – Authentication for SQL Server

The issue with a one hour webcast is one can’t cover a broad topic like application database security design in any depth. However, these webcasts are useful because they point out, at a high level, what to look for. It was my intent all along to do the webinar and follow up with a series of articles that cover each topic in detail. I’m not sure how many articles I’ll end up writing, as I want to make sure I cover each topic in the depth it needs while still keeping the article length manageable.

This first post is all about comparing and contrasting credentials options and authentication methods.

The Value Of SQL Browser

Chris Sommer points out that the SQL Browser does something useful:

Bingo. The application server could not connect to the SQL Browser service on UDP 1434. So maybe now you’re asking why, and that’s kinda the gist of this post. The SQL Browser provides a valuable service when an application tries to connect to a SQL Server named instance. The SQL Browser listens on UDP 1434 and provides information about all SQL Server instances that are installed on the server. One of those pieces of information is the TCP port number that SQL is listening on. Without that info, the application has no idea how to reach to your SQL Server, and will fail to connect. This was our exact issue.

Do read this, though my preference is to shut off the SQL Browser because it’s a mechanism attackers can use for gathering intel on where SQL Server instances live.

Understanding Database Role Permissions

Jason Brimhall shows what happens when you make a user a member of every database role at the same time:

A fundamental component of SQL Server is the security layer. A principle player in security in SQL Server comes via principals. In a previous article, I outlined the different flavors of principals while focusing primarily on the users and logins. You can brush up on that article here. While I touched lightly, in that article, on the concept of roles, I will expound on the roles a bit more here – but primarily in the scope of the effects on user permissions due to membership in various default roles.

Let’s reset back to the driving issue in the introduction. Frequently, I see what I would call a gross misunderstanding of permissions by way of how people assign permissions and role membership within SQL Server. The assignment of role membership does not stop with database roles. Rather it is usually combined with a mis-configuration of the server role memberships as well. This misunderstanding can really be broken down into one of the following errors:

  • The belief that a login cannot access a database unless added specifically to the database.

  • The belief that a login must be added to every database role.

  • The belief that a login must be added to the sysadmin role to access resources in a database.

Worth reading.  Spoilers:  database roles are not like Voltron; they don’t get stronger when you put them all together.

SQL Authentication Accounts Without Password Policy

Chris Bell shows how to find accounts using SQL authentication and which do not have the “enforce password policy” flag set:

Recently I was performing a security audit for a client. One of the many things I had to check was the enforcement of password policies for any SQL Server created accounts.

You know, that policy that says you must have some combination of 6 or more characters, upper and lower case, a number, and special characters, etc.

These policies are controlled by the server policy settings and were something easy to check. The actual passwords and that they were safe, not so much.

Click through for the script.

Encryption In Progress Stuck

Arun Sirpal tried to enable Transparent Data Encryption but his database was stuck in the “Encryption in progress” status:

My ZoraDB database clearly stuck in an encryption in progress state.

With the database being small the encryption process should not take long at all, I was confused.

I then decided to try and turn off the encryption.

Read on for the solution.

Server-Level Database Permissions

Kenneth Fisher shows off some special server-level permissions:

So what’s our shiny new permissions toy? Well, over time we have been getting more and more server level permissions that affect database level objects. A lot of these can be really useful and I’m hoping we will see more and more of them.

Click through for a couple helpful tables of permissions.

Managing Azure SQL Database Firewall Rules

Cedric Charlier shows how to manage Azure SQL Database firewall rules from within Management Studio:

When you create a new Azure database, you usually need to open the firewall to remotely administrate or query this database with SSMS. An option is to create rules from the Azure Portal. It’s surely a convenient way to do it when you create a database but I prefer to keep a minimum of tools and when the Azure portal is not open, I prefer to not have to open it just to define a few firewall rules.

Opening the firewall with SSMS is a kind of chicken and eggs problem: to connect to your database/server, you need to open the firewall. Hopefully, SSMS has a great suite of screens to call the underlying API of Azure Portal and open the firewall for the computer running SSMS.

Cedric shows off sp_delete_firewall_rule but there’s also a corresponding sp_set_firewall_rule.

Always Encrypted Data And SSMS

Justin Goodwin shows how to view Always Encrypted data from within Management Studio:

I am now able to view the encrypted data. Why is this?

Because I am connecting to the database from the database server, I have access to the Encryption Certificate that was generated. I can verify this by opening certmgr.msc and browsing to Personal -> Certificates:

Justin then goes on to show what happens when you don’t have access to the certificate and how to provide access to another machine.


April 2017
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