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Category: Security

Scripting Out Linked Servers with Actual Passwords

Published 2019-10-29 by Kevin Feasel

Ajay Dwivedi shows how you can script out a linked server creation statement which includes actual passwords:

For moving Logins/Users, Microsoft provided revlogin script which made it easy for migration of logins without need to know about passwords. But, there is no easy approach for migration LinkedServers with the actual password. This is where dbatools cmdlet Copy-DbaLinkedServer becomes very handy. But, what about the situation where we have to script out LinkedServer beforehand.

For this reason, based on the blog post of Antti Rantasaari, and using his code as the base script, I have created a cmdlet Get-LinkedServer with SQLDBATools module which accepts SqlInstance name as a parameter along with -ScriptOut switch, and gives Drop/Create statements for linked servers present on that local/remote SqlInstance.

As a quick note, SQLDBATools is not the same as dbatools.

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Azure AD Credential Passthrough and Databricks

Published 2019-10-28 by Kevin Feasel

Anna Shrestinian, et al, explain how Azure Databricks enables Azure Active Directory credential passthrough when working with Azure Data Lake Storage Gen2:

Azure Data Lake Storage (ADLS) Gen2, which became generally available earlier this year, is quickly becoming the standard for data storage in Azure for analytics consumption. ADLS Gen2 enables a hierarchical file system that extends Azure Blob Storage capabilities and provides enhanced manageability, security and performance.

The hierarchical file system provides granular access control to ADLS Gen2. Role-based access control (RBAC) could be used to grant role assignments to top-level resources and POSIX compliant access control lists  (ACLs) allow for finer grain permissions at the folder and file level. These features allow users to securely access their data within Azure Databricks using the Azure Blob File System (ABFS) driver, which is built into the Databricks Runtime.

There are some tradeoffs involved, particularly around using High Concurrency clusters (or limiting yourself to one user account), but it’s a nice bit of added value when you’re a heavy Azure user.

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skip-2.0 and SQL Server Security

Published 2019-10-28 by Kevin Feasel

K. Brian Kelley has the lowdown on skip-2.0:

Problem
I’ve read recently that there’s a new piece of malware that’s been named skip-2.0 and it targets SQL Server. What exactly is it, where did it come from, and how do I protect myself against it?

Solution
This new piece of malware, skip-2.0, does target SQL Server. Specifically, it targets SQL Server versions 11 and 12, which correspond to the names SQL Server 2012 and SQL Server 2014 respectively. Therefore, if you’re only running SQL Server 2016 or higher, you’re not affected by skip-2.0 (yet another reason to upgrade).

Read on to learn how it works and how you can protect against it.

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JDBC Resource Pools and Kerberos

Published 2019-10-23 by Kevin Feasel

Guy Shilo has a tip for us around JDBC connectivity when your Hadoop cluster is configured for Kerberos:

This is a quick tip about connecting to Hive or Impala via JDBC.

Accessing hive or impala using their JDBC driver is very convenient. Client programs s like beeline or Jetbrains DataGrip use it as the main way of accessing Hive/Impala and many people also use it in their own written programs.

Things get a little trickier when the cluster is kerberized. In this case you should add few extra parameters to the JDBC connect string.

Read on to see what to do.

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PowerApps Security

Published 2019-10-22 by Kevin Feasel

Jason Bonello gives us some tips on PowerApps security:

Depending on how the backend is set up, the tables having these sensitive data might be in the same database. For example, ERP solutions can have Company Accounts data, Customer related data and Inventory related data all in the same database, maybe under different schemas – but still part of the same database.

Now let’s say we are about to create a PowerApps solution to maintain Customer information. However, as part of the organization policy, this information should not be shared across other departments apart from the intended users.

Read on for some ideas of how to limit the risk of data exposure.

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Mapping Usernames within the Power BI Gateway

Published 2019-10-15 by Kevin Feasel

Jeff Pries takes us through a difficult scenario:

With some data sources, such as Analysis Services, you want to pass the username of the person running the report back to the server executing the query (such as in a Row Level Security configuration). Adam Saxton of Guy in a Cube does a great job of explaining how this works at a high level in the video linked here.

In the video, Adam mentions that if our Power BI login does not match a UPN in our local Active Directory, then the lookup will fail…which is a problem if you just don’t have the option of having your Power BI login match a UPN in your local Active Directory and don’t want to manage static user mappings over time. The following will cover a method of allowing the lookup to use a different Active Directory property, such as “mail” to perform the matching.

Read on for the steps.

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Tracking Security Changes with the Default Trace

Published 2019-10-09 by Kevin Feasel

Jack Vamvas shows how we can use the default trace with SQL Server to find security-related events:

Question: There were some recent user security changes on a SQL Server login user account. Is there a way to grab this information – via the default trace? I haven’t got a dedicated Extended events monitor set up – so I’m relying on the default trace . Management want to understand the details related to this security change. 
 
Answer: It is possible to report on security changes administered on SQL Server via the default trace. In fact – it’s excellent – except if the default trace configuration is set up to rollover the files.

Read on to see how.

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Bulk Removing Reshare Permissions in Power BI

Published 2019-10-08 by Kevin Feasel

Gilbert Quevauvilliers takes us through bulk changing dataset permissions in Power BI:

Whilst this sometimes is what is required, I always suggest to people to remove this option and rather manage it by exception.

If you do leave this option enabled, it means if I had to share a report with Bob, Bob would then be able to reshare the report with someone else. This could potentially lead to other people gaining access to a report or data that they should not see.

Fortunately, I found a way to quickly remove the reshare option in the Power BI Service.

Click through to see how it’s done.

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Mitigating SQL Injection with SQL Server 2019

Published 2019-10-08 by Kevin Feasel

Grant Fritchey is sick of SQL injection:

Instead, let’s talk about some of the common vectors of SQL Injection. Obviously, building and executing strings is the biggest issue. Appropriate use of parameters will do more to the fix the problem than almost any other step. However, it’s also enhanced by bad code on the front-end which doesn’t appropriately clean the data, inappropriate error handling, bad security, bad data isolation, and more.

The keys to the attack are to get back a few bits of information, usually in error messages in the case of a normal attack, or, through the use of the WAITFOR command in a blind attack (for more detail, I’m talking about this stuff at the PASS Summit). Getting error messages with information about the database makes it easier for me to hack your system (if I was evil). Knowing that I have a SQL Injection vector through the WAITFOR command helps me target appropriate systems (if I was evil).

For the most part, SQL injection isn’t a SQL problem—it’s an application problem (save for the case when you generate dynamic SQL and concatenate in input parameters). SQL Server-based solutions will only do a little bit; fixing the app code is the best answer.

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Listing Windows Users with Powershell

Published 2019-09-27 by Kevin Feasel

Jack Vamvas shows us how we can use Powershell to list Windows users in an Active Directory group:

Question: How can I use Powershell to list out Windows users? Are there Powershell cmdlets which can report on Windows users ?
Answer: There are “out of the box” Powershell cmdlets which will support the requirement . How you apply the powershell cmdlets will depend on how much detail is required.

Jack has a few examples here as well.

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