The Workplace Ninja Summit takes place from 12-14 September 2022 in Lucerne, Switzerland. The conference focuses on endpoint management and security with platforms such as System Center Configuration Manager (SCCM) and Microsoft Endpoint Manager/Intune.
Conference Sessions
If you are participating in the conference, be sure to attend one of my sessions! I’m delivering the following three talks during the event.
This session will explore the options for deploying enterprise PKI certificates using Intune. I’ll be sharing lots of security and implementation best practices.
This talk will dive into the options for deploying Always On VPN using Intune. I’ll be covering many tips, tricks, and best practices and shining a light on many limitations and shortcomings of using Intune for Always On VPN.
Join Me!
Unfortunately, the conference is sold out, so if you haven’t made arrangements to attend you’ll have to wait until next year. If you are attending, please be sure to say hello!
Microsoft introduced important changes affecting certificate-based authentication on Windows domain controllers as part of the May 10, 2022 update KB5014754 that may affect Always On VPN deployments. The update addresses privilege escalation vulnerabilities when a domain controller is processing a certificate-based authentication request. The recommendation from Microsoft is that the update be applied to all Windows domain controllers and Active Directory Certificate Services (AD CS) servers as soon as possible.
After applying the update to certification authority (CA) servers, a non-critical extension with Object Identifier (OID) 1.3.6.1.4.1.311.25.2 is added to all issued certificates with the user or device security identifier (SID) included. Domain controllers with the update installed will use this information to validate the certificate used for authentication and ensure that it matches the information in Active Directory.
Domain Controllers
The update operates in Compatibility Mode, by default, when applied to domain controllers. Windows monitors authentication requests and records audit events for certificates presented for authentication under the following conditions.
No strong mapping (event ID 39) – The certificate has not been mapped explicitly to a domain account, and the certificate did not include the new SID extension.
Certificate predates account (event ID 40) – A certificate was issued before the user existed in Active Directory, and no explicit mapping could be found.
User’s SID does not match certificate (event ID 41) – A certificate contains the new SID extension, but it does not match the SID of the corresponding user account.
Certificate Mapping
Administrators can map certificates explicitly to accounts in Active Directory, but this results in a significant administrative burden in most environments. A better option is to reissue user and device authentication certificates after applying the KB5014754 update to all issuing CA servers.
Reenroll Certificates
Administrators should reissue user and device authentication certificates after applying the KB5014754 update. Open the Certificate Templates management console (certtmpl.msc), identify the user or device authentication certificate template, then right-click on the template and choose Reenroll All Certificate Holders.
Enforcement Mode
After applying update KB5014754, administrators should monitor domain controller event logs for event IDs 39, 40, and 41. Once all certificates have been updated, and none of these events have been recorded for 30 days, administrators can switch to Full Enforcement Mode by enabling it in the registry on all domain controllers.
Updated 12/8/2022: Microsoft has pushed back the original enforcement date of May 9, 2023, to November 14, 2023 “or later”. Stay tuned!
Known Issues
There have been some reports of authentication issues after installing the KB5014754 update. Early indications are that device authentication certificates missing a Subject Alternative Name (SAN) entry are to blame. Administrators are encouraged to update their device certificates to include the SAN entry. Optionally, but not recommended, administrators can place the update in disabled mode by editing the registry.
Note: An out-of-band update for these authentication issues is now available. See the reference links at the top of this article for more information.
Caveat
It’s important to understand that this new OID is added only to online templates. Online templates are those that build the subject information from Active Directory. Unfortunately, this new OID is NOT applied to offline templates (templates where the subject name is supplied in the request), such as those used for delivering certificates with Microsoft Endpoint Manager/Intune using PKCS or SCEP. It is impossible to move to enforcement mode when issuing user or device authentication certificates with Microsoft Endpoint Manager or Intune today. Microsoft is aware of this limitation and is working to address this issue as we speak. I expect a fix to be available sometime before the May 2023 deadline when Microsoft permanently switches on enforcement mode.
I am excited to announce that I will be presenting at this year’s Midwest Management Summit at the Mall of America (MMSMOA) in Bloomington, Minnesota. The conference takes place the week of May 2. This is my first time presenting at this event, and I’m looking forward to sharing my experience deploying enterprise mobility and security infrastructure solutions with systems management professionals from around the world.
Sessions
I will be delivering three talks at the conference addressing various secure remote access and certificate services topics.
Managing Always On VPN with Intune
This session will provide administrators with everything they need to know about provisioning and managing Always On VPN client configuration settings using Intune. I’ll be providing tips, tricks, and best practices for Always On VPN profile configuration and demonstrating many of the limitations associated with using Intune. I will provide workarounds whenever possible.
Deploying Always On VPN in Azure is increasingly common. However, administrators are unaware of the limitations of supporting Always On VPN connections with native Azure VPN gateway solutions. In this session, I’ll describe in detail what’s required to support Always On VPN and, importantly, what the limitations are.
Deploying On-premises PKI Certificates with Intune
As organizations continue to migrate applications, services, and infrastructure to the cloud, the requirement for endpoints to be joined to an on-premises domain is fading. Moving to full Intune management and native Azure Active Directory join for endpoints is increasingly common. However, deploying enterprise PKI certificates o these endpoints is often required. This session will provide detailed guidance for choosing the best solution to deliver on-premises certificates to Azure AD joined devices using Intune.
I’m looking forward to meeting so many folks who have helped me get up to speed with Microsoft Endpoint Manager/Intune over the years. If you’re attending the conference, or if you are in the area, be sure to reach out. Let’s grab a beer and chat!
