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Category: Security

Security Breach in Cosmos DB: ChaosDB

Published 2021-08-27 by Kevin Feasel

Nir Ohfeld and Sagi Tzadik discovered a flaw in Azure Cosmos DB:

Nearly everything we do online these days runs through applications and databases in the cloud. While leaky storage buckets get a lot of attention, database exposure is the bigger risk for most companies because each one can contain millions or even billions of sensitive records. Every CISO’s nightmare is someone getting their access keys and exfiltrating gigabytes of data in one fell swoop.

So you can imagine our surprise when we were able to gain complete unrestricted access to the accounts and databases of several thousand Microsoft Azure customers, including many Fortune 500 companies. Wiz’s security research team (that’s us) constantly looks for new attack surfaces in the cloud, and two weeks ago we discovered an unprecedented breach that affects Azure’s flagship database service, Cosmos DB.

Read on for details about the attack. Microsoft has already mitigated the issue by disabling the functionality necessary to pull off the attack. H/T Ben Stegink.

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The Cost of a Checkbox: Power Apps Edition

Published 2021-08-24 by Kevin Feasel

Paul Thurrott looks at a security issue:

Over 1000 web apps created with Microsoft’s Power Apps inadvertently exposed the data from over 38 million users thanks to a misconfiguration, according to a new report in Wired. The good news? The issue has been fixed and no customers are known to have been compromised.

“We found [a web app created with Power Apps] that was misconfigured to expose data and we thought, we’ve never heard of this, is this a one-off thing or is this a systemic issue?” UpGuard vice president Greg Pollock told Wired. “Because of the way the Power Apps portals product works, it’s very easy to quickly do a survey. And we discovered there are tons of these exposed. It was wild.”

“Known to have been compromised” probably needs a “yet” in there somewhere. Read the whole thing.

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Kafka and SIEM/SOAR Tools

Published 2021-08-12 by Kevin Feasel

Kai Waehner wraps up a series on Apache Kafka and network security:

SIEM combines security information management (SIM) and security event management (SEM). They provide analysis of security alerts generated by applications and network hardware. Vendors sell SIEM as software, as appliances, or as managed services; these products are also used for logging security data and generating reports for compliance purposes.

SOAR tools automate security incident management investigations via a workflow automation workbook. The cyber intelligence API enables the playbook to automate research related to the ticket (lookup potential phishing URL, suspicious hash, etc.). The first responder determines the criticality of the event. At this level, it is either a normal or an escalation event. SOAR includes security incident response platforms (SIRPs), Security orchestration and automation (SOA), and threat intelligence platforms (TIPs).

In summary, SIEM and SOAR are key pieces of a modern cybersecurity infrastructure. The capabilities, use cases, and architectures are different for every company.

Click through to see where Kafka can fit in all of this.

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Row Level Security in Azure Analysis Services and Power BI PPU

Published 2021-08-11 by Kevin Feasel

Gilbert Quevauvilliers continues a series on moving from Azure Analysis Services to Power BI Premium Per User:

In this blog post I am going to cover how to implement Row Level Security (RSL) when using AAS and how this can be done on PPU.

In my example below I am going to show creating to simple RLS roles which will limit data for the users who belong to 2 roles.

Despite the simplification, we can see how row-level security applies to both products and how the two differ.

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Finding and Removing Custom Roles, Schemas, and Users from a Database

Published 2021-08-05 by Kevin Feasel

Thomas Williams wants to go back to square one:

I’m a fan of the built-in database roles like db_datareader to standardise & simplify permissions (sorry Dr. Greg Low!) and recently I needed to do just that in a database created using SQL Server 2000, and remove old defaults and a lot of custom roles, schemas and users.

I wrote the set of queries below to generate scripts to remove non-built-in roles, schemas and users, when compared to the model database on a new SQL Server 2019 server.

After running the script generated by the queries, I added back users and gave appropriate roles (like db_datareader).

Read on for the script.

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Executing T-SQL with a Proxy Account

Published 2021-08-04 by Kevin Feasel

Tom Collins answers a question:

I have some t-sql code added to a job step on a SQL Server Agent job. The problem is I need to run the code as RUNAS . I though of executing the job with a proxy account – so progressed with the Credential & proxy set up.    But I still can’t view the Proxy\Credential in the RunAs list . Is there a way around this problem?

Read on to learn why and for the answer.

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A Warning: VPCs and Distributed Database Platforms

Published 2021-08-02 by Kevin Feasel

Wade Trimmer takes us through a reason why you might not want to use VPC endpoints to separate applications from distributed database platforms:

AWS PrivateLink (also known as a VPC endpoint) is a technology that allows the user to securely access services using a private IP address. It is not recommended to configure an AWS PrivateLink connection with Apache Kafka or Apache Cassandra mainly due to a single entry point problem. PrivateLink only exposes a single IP to the user and requires a load balancer between the user and the service. Realistically, the user would need to have an individual VPC endpoint per node, which is expensive and may not work. 

Using PrivateLink, it is impossible by design to contact specific IPs within a VPC in the same way you can with VPC peering. VPC peering allows a connection between two VPCs, while PrivateLink publishes an endpoint that others can connect to from their own VPC.

Read on to understand how this affects platforms like Cassandra and Kafka.

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Working with App Secrets in .NET Core

Published 2021-07-30 by Kevin Feasel

Santosh Hari shows us how to use application secrets when building .NET Core applications:

I was writing a sample dotnetcore console application for a talk because why I felt using a sample aspnet core web app was overkill. The app was connecting to a bunch of Azure cloud and 3rd party services (think Twilio API for SMS or LaunchDarkly API for Feature Flags) and I had to deal with connection strings.

Now I have a nasty habit of “accidentally” checking in connection string and secrets into public GitHub repositories, so I wanted to do this right from the get go.

That’s a bad habit to be in, and Santosh shows us how we can avoid doing that via use of application secrets.

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Handling Content Access Requests in Power BI

Published 2021-07-30 by Kevin Feasel

Marc Lelijveld walks us through the process of requesting (and granting) access to content in Power BI:

When we look at the Power BI ecosystem, we can identify a bunch of different artifacts. For example, dataflows, datasets, reports, dashboards and many derivatives. As I explained in the previous post, the best practice for sharing content is through a Power BI App, which includes a list of users or active directory group containing multiple users. With that, the content becomes available after publishing to those who are granted access. Though, it can happen that one of the users shares the link with other users who do not have access to the content. As a property of the Power BI App, you can allow users to share the app and underlying dataset with share permissions. Though, working with sensitive data this might now be what you are looking for, as you might loose control over who has access.

Read on to see what constitutes a content access request and what you can do about them.

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