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27/06/2026 1:19 pm
TL;DR: Microsoft 365 misconfigurations, including legacy authentication and overly permissive OAuth apps, create attacker entry points that can bypass MFA, sustain access, and hide in plain sight, according to Abnormal AI. The real issue is not tool count, but governance drift across identity settings that security teams do not consistently govern.
NHIMG editorial — here’s why we think this discussion matters
By the numbers:
- When AWS credentials are exposed publicly, attackers attempt access within an average of 17 minutes.
- Lack of credential rotation is cited as the top cause of NHI-related attacks by 45% of organisations.
Questions worth separating out
Q: How should security teams reduce Microsoft 365 identity risk from misconfigurations?
A: Start by treating Microsoft 365 as an identity control plane, not a collection of apps.
Q: Why do legacy authentication and OAuth abuse increase Microsoft 365 compromise risk?
A: Legacy authentication can bypass modern assurance controls, while OAuth abuse can convert delegated permission into persistent access.
Practitioner guidance
- Disable legacy authentication where possible Map all remaining legacy protocol dependencies, remove exceptions that are no longer business-critical, and require explicit approval for any residual use.
- Review OAuth app consent and scope sprawl Inventory all third-party and internal OAuth apps, confirm current business ownership, and remove broad scopes that are not required for the app’s stated purpose.
- Tie configuration drift to identity review cycles Fold Entra, Teams, and Exchange misconfiguration checks into recurring access reviews so the team is not only reviewing users, but also the settings that govern how users and apps authenticate and persist.
What to expect at the briefing
Abnormal AI's full webinar covers the operational detail this post intentionally leaves for the source:
- Walkthrough of how legacy authentication and OAuth abuse are used in real attack chains across Microsoft 365.
- Examples of Teams and Entra misconfigurations that were exploited in the wild, including the control failures behind them.
- How Abnormal's Security Posture Management identifies blind spots and prioritises remediation across the tenant.
- The CPE-eligible webinar format and on-demand access details for practitioners who want the source presentation context.
👉 Watch Abnormal AI's on-demand webinar on hidden Microsoft 365 entry points →
Microsoft 365 misconfigurations: are your identity controls keeping up?
Explore further
27/06/2026 2:37 pm
Microsoft 365 misconfiguration is an identity governance problem, not just a hardening problem. The article shows that legacy authentication, OAuth abuse, and uneven access controls create alternative trust paths inside the same tenancy. That means the issue spans human IAM, app consent governance, and NHI-style delegated access. Practitioners should treat configuration drift as a standing identity risk rather than a one-time hygiene issue.
A few things that frame the scale:
- 85% of organisations lack full visibility into third-party vendors connected via OAuth apps, and 38% have no or low visibility, according to The State of Non-Human Identity Security.
- A separate finding shows that only 1.5 out of 10 organisations are highly confident in their ability to secure NHIs, which helps explain why delegated access risks often outpace governance.
A question worth separating out:
Q: Who should own remediation when Microsoft 365 misconfigurations create exposure?
A: Ownership should sit with both IAM governance and the platform team, because the risk spans identity policy and service configuration. If an issue affects authentication, consent, or persistent access, it needs a named accountable owner and a closure path. Absent that, misconfigurations survive across changes, exceptions, and tenant growth.
👉 Read our full editorial: Microsoft 365 misconfigurations expose hidden identity entry points
