linkservers no longer working after applying KB5024276

Question

Hi there, After applying sqlserver2019-kb5024276-x64, most of my link servers are erroring with either SSL = expiredcert or certchainnottrusted. I have the same Production equivalent server without kb5024276 and it works fine. The linkservers are fqdn representations and they are using the default, Microsoft OLE DB Driver for SQL Server. The same result when I test using udl. Further, I can connect to these same servers fine through ssms/regsrvr/osql/sqlcmd. I assume kb5024276 updates MSOLEDBSQL driver, since add/remove shows it as 18.6.5.0 updated on 2023-04-17, and the PRD server is at 18.3.0.0. The release notes shows that this driver is updated, but not sure what changed that is breaking these.
I would rather not uninstall/reinstall old version as kb5024276 is part of the recently announce CVE-2023-23384 from this month. Anyone have any guidance on this, would be appreciated, as I couldn't find any related posts for kb5024276 severing linkservers/msoledbsql, thank you kindly.
Regards,
Pierson
pGwtech

Answer 1

Hi Pierson, Welcome to Q&A Forum; this is a great place to get support, answers, and tips. Thank you for posting your question; I'll be more than glad to help you out.

Maybe your googling for any known issues was too early ;-) If you take a look at the official CU20 documentation, you will find at least two known issues; one is related to MSOLEDBSQL...

Msg 7320, Level 16, State 110, Line 68 Cannot execute the query "Remote Query" against OLE DB provider "MSOLEDBSQL" for linked server "(null)". Object reference not set to an instance of an object.

https://support.microsoft.com/en-us/topic/kb5024276-cumulative-update-20-for-sql-server-2019-4b282be9-b559-46ac-9b6a-badbd44785d2#known

I hope my answer is helpful to you, Your Bjoern Peters

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