Stop the Bleeding: Cleaning Up Apps, Secrets and Consent in Microsoft Entra

Most tenants have the same problem: hundreds of app registrations and service principals, client secrets that were set to expire in a hundred years, permission grants nobody remembers approving, and test tenants that were never cleaned up. It’s tempting to start fixing the scariest app on the list. Jeff Sakowicz argues for a different order: stop the problem from growing first, then remove the debt that gives you the most risk reduction for the least disruption.

Jeff isn’t describing someone else’s product. He has spent most of his 14 years at Microsoft as a product leader on the Entra application platform, shaping the application and service principal model and the OAuth permissions and consent model that every Entra tenant runs on today. Publisher verification and risk-based step-up consent came out of that work, and he now leads part of the team building the platform behind Microsoft Entra Agent ID. Inside Microsoft, he’s the person teams call when an app incident needs untangling. This is his playbook for securing non-human identities, from client secret burndown and unused apps to consent phishing and the protections Microsoft runs in every tenant by default.

Prevention starts with policy

The best medicine is prevention. Before you clean anything up, go through the policy controls you already have and set them to block insecure configuration that doesn’t fit your organization’s risk tolerance. This is a balance, not a switch. “If you want the most secure system in the world, unplug the server, bury it underground. Your job is done.” Lock things down too hard and developers and end users will find other ways to get work done, especially now that they have agents to help them. Shadow IT is almost always less secure than what you stopped. So whenever a control blocks self-service, make sure people know what to do next and how to get unblocked quickly.

Treat high-value apps as production infrastructure

Microsoft runs customer-facing apps in tenants separate from its corporate tenant. Tenant-level isolation is a useful form of segmentation, and some large organizations do the same for their production assets. But a second tenant brings its own operational overhead, and a tenant that falls into chaos can leave you worse off than before.

Whatever you decide, treat your multitenant apps and high-value line-of-business apps as production infrastructure, the same way you would protect a database or a high-value Azure subscription. A good middle ground is to keep a close eye on the owners and sponsors of your high-value apps and agent identities. They are the people who can change those identities’ authentication configuration, so their accounts need good hygiene.

The easier win is test, demo and staging. If they still live in your productivity or production tenant, move them out. Midnight Blizzard showed how small dominoes lead to big consequences: Microsoft’s own write-up describes a password spray against a legacy, non-production test tenant account, followed by a legacy test OAuth application that had elevated access to the corporate environment.

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Maester Cloud turns those results into a workflow your team can run every day:

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Map your surface area, then think in three dimensions

Before buying a new inventory tool, use the one you already have. If your organization already tracks production assets or other identities, bring your non-human identities into that system instead of running a parallel process. Then answer three questions: how many of these do I have, what categories of identity are in the portfolio, and what are the big categories of risk?

Jeff looks at risk in three dimensions:

* Active threats. Priority zero. Hand them to the SOC immediately.

* Posture. Surface area from misconfiguration, or configuration that was state of the art five years ago, such as the implicit flow for a single-page app. Weak credentials, insecure redirect URIs, unused identities and legacy protocols all live here.

* Blast radius. How much privilege each identity has, whether it’s used or not.

Most organizations end up with a huge list of high-privilege apps and posture issues. You will never get every risk to zero at that scale, so the job is to prioritise by risk and by return on effort.

Burn down secrets: stop the bleeding first

Say you’ve read the Solorigate reports and want to get client secrets off your non-human identities. Step one is to stop the bleeding: create an app management policy that blocks new password credentials from being added. App management policies can take an enforcement date, so only apps created after that date are affected and your hundreds of existing apps keep working while you fix them. There is no equivalent for user authentication methods.

Before you switch it on, find out how disruptive it will be. One new app a month that uses a password credential is easy to absorb. A hundred a day could grind the organization to a halt. Have the guidance and the exception process ready, and move the enforcement date if you need to.

Once the problem has stopped growing, turn to the debt. Split it into categories and start with the two ends of the spectrum:

* The most privileged. Apps with existing passwords that have app-only access to read all mailboxes or read and write all user profiles go to the top of the list. Move them to a stronger credential and check whether they need that access at all.

* The wholly unused. More on this below.

The end goal is system-managed credentials, using a managed identity or workload identity federation with a federated identity credential (FIC). You can argue a certificate’s private key is harder to leak than a secret, but as Jeff says, “a bad copy-paste is a bad copy-paste.” System-managed credentials also remove a big source of toil for developers, which helps when you need people to move.

Why mail is the flag

Mail permissions can look less frightening than broad directory permissions, but for many attacks mail is the goal. “Mail’s often the flag that the attacker’s trying to capture.” Other access is often just a way to move laterally or elevate privilege. Mail, Teams chats and files can be the end goal, and that is what most historical consent phishing attacks went after. A mailbox is also a good lateral movement tool: it can hold credentials and bank details, and it gives an attacker what they need to craft a convincing social engineering attack against everyone the victim emails or chats with every day.

Lost secrets make this worse. A secret that is valid for years, used by apps nobody can name, gives an attacker a way in without adding a new credential, so there’s no new event for you to trace.

Unused identities: the highest return on effort

A wholly unused identity is the highest-ROI bucket. “If you get rid of an unused identity, you might be knocking an item off of seven lists.” In one move you can remove a weak password, an insecure redirect URI, overprivileged access and some legacy protocol usage. Do your due diligence first, because some apps only run once a year at tax season. But removing something that is truly unused doesn’t disrupt anyone, and it can be done as a central action by a single team without engaging every app owner. That high-leverage central action is what Microsoft leaned into for its Secure Future Initiative work.

Then look at low-usage identities. They hide in plain sight: an identity with an automated runner that wakes up every day to run a test…

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