Logins, SIDs, and Kerberos from First Principles, Part 7: Is Your Kerberos Still Using RC4?
got your connections onto Kerberos. This part asks an uncomfortable follow-up: encrypted with what? You probably have not thought about Kerberos encryption types recently. That is fair; the protocol mostly just works and has for…
Logins, SIDs, and Kerberos from First Principles, Part 6: SPNs and the Silent NTLM Fallback
The first five parts of this series were about who you are: SIDs, logins, groups. This one is about how you prove it. When a Windows principal connects to SQL Server with integrated authentication, one…
Is Your SQL Server Using RC4 for Kerberos? Here’s How to Find Out
You probably haven’t thought about Kerberos encryption types recently. That’s fair; the protocol mostly “just works” and has for decades. But CVE-2026-20833 changed the calculus. Microsoft disclosed a Kerberos information disclosure vulnerability in January 2026…
Inspecting SQL Server TLS Certificates Without Credentials
If you’ve ever needed to check the TLS certificate on a SQL Server instance – whether it’s expired, misconfigured, missing SANs, or just plain self-signed – you’ve probably had to connect with SSMS, run some…
BULK INSERT, Kerberos, and Delegation
Pesky Kerberos and BULK INSERT The T-SQL commands, BULK INSERT and OPENROWSET(…), offer great ways to import data from a file into a table in SQL Server. However, getting BULK INSERT Kerberos security setup correctly…
Enable Kerberos Authentication without rebooting SQL Server
What is this Kerberos thing, anyway?! Kerberos Authentication1 allows SQL Server to impersonate Active Directory users to other services via double-hop-authentication. This is commonly used to provide access to data through a web-site via Windows…