This One Actually Got Exploited Before the Patch Landed
Most Microsoft patches are theoretical. Someone found a bug, reported it, Microsoft fixed it, and the odds that anyone targeted your business with that specific flaw are pretty low. This Entra ID vulnerability is different. It was already being used in real attacks before the patch came out. That changes the urgency level considerably.
Entra ID is Microsoft’s identity platform. If your business uses Microsoft 365, Azure, or anything that relies on single sign-on, Entra ID is sitting in the middle of your authentication stack. It’s how your people prove who they are before they get access to email, SharePoint, Teams, or any connected app. A flaw there isn’t a minor inconvenience. It’s a direct path into your environment.
What “Maximum Severity” Actually Means for a Small Business
Microsoft uses a severity rating system, and “critical” or “maximum severity” means the vulnerability can be exploited remotely, without the attacker needing prior access, and the potential damage is significant. In this case we’re looking at code execution and privilege escalation. Code execution means an attacker can run their own software on your systems. Privilege escalation means they can move from a low-level account to something with admin rights.
Put those two together and you have a realistic path to a full account takeover or a ransomware deployment. I’ve seen businesses hit with far less sophisticated attack chains than this.
Small businesses often assume they’re not targets. They are. Automated scanning tools don’t care how big your company is. They look for vulnerable systems at scale, and if yours shows up, it gets hit.
The Immediate Priority: Verify the Patch Is Applied
Microsoft has released the fix. Your job right now is confirming it’s actually been applied in your environment, not just assuming it has.
If you manage your own Microsoft 365 tenant, log into the Microsoft 365 admin center and check your service health and update status. If you’re using Intune for device management, pull a compliance report and look for any devices that are out of date on patches. If you’re running Windows Update for Business through group policy, verify your update rings are current and that nothing is stuck in a deferral window longer than a week or two.
The patch for Entra ID itself is on Microsoft’s side, meaning it doesn’t require you to push something to every workstation. But related Windows patches that address the privilege escalation component do need to reach your endpoints. That’s the piece most small businesses miss.
Conditional Access Is Your Backup Defense
Patching is step one. The longer-term move is making sure your Entra ID configuration isn’t leaving doors open even after patches are applied.
Conditional Access policies in Entra ID let you set rules around how and when users can authenticate. You can require multi-factor authentication for all sign-ins, block logins from geographic regions you don’t operate in, and require compliant devices before granting access to sensitive apps. If you don’t have these policies configured, you’re relying entirely on passwords and patches to keep attackers out. That’s not enough.
MFA alone blocks the vast majority of credential-based attacks. It takes about an afternoon to set up properly for a small tenant, and it’s included in most Microsoft 365 Business plans. There’s no good reason not to have it.
What to Actually Do This Week
First, confirm your Windows devices are current on the latest cumulative update from Microsoft. Second, log into Entra ID and check that MFA is enforced for all users, especially admins. Third, review your Conditional Access policies or create them if you haven’t. Fourth, check whether any accounts show unusual sign-in activity in the Entra ID sign-in logs. Filter for failed attempts or logins from unexpected locations.
If you’re not sure where to start or you don’t have someone watching this stuff regularly, that’s a real gap. Exine works with small and mid-size businesses across New Jersey and New York City to keep Microsoft environments patched, monitored, and configured correctly. We’re happy to take a look at where you stand.
