Apps with Admin Roles: Privileged Service Principal Abuse Risk

When an application or service principal is assigned a privileged Entra ID role — Global Administrator, Exchange Administrator, Directory Writer, or similar — it operates with the same access as a human admin but without the same controls. There is no MFA prompt. There is no Conditional Access check. There is no sign-in risk evaluation. The only protection is the security of the application's credentials.

Overe flags applications and service principals holding Entra directory roles, particularly privileged ones. While some automation scenarios legitimately require elevated permissions, an app with a high-privilege role is a high-value target. Compromising the app's client secret or certificate is functionally equivalent to compromising an admin account — without any of the human-layer protections.

Many of these role assignments accumulate over time — created for a migration or automation task, never removed after the project closed, or inherited from a template without review.

• Attacker steals an app client secret and authenticates as a Global Admin with no MFA or Conditional Access challenge
• Privileged service principal used to create new admin accounts, modify role assignments, or disable security controls
• Entra directory modified silently — users added to groups, permissions changed, policies adjusted — without any human sign-in trail
• App credentials embedded in code repositories or configuration files exposed in a breach
• Backdoor admin account created and persisted through the service principal without appearing in normal admin sign-in activity
• Entire tenant configuration accessible and modifiable with no interactive authentication required

Some legitimate automation scenarios require elevated permissions. Provisioning tools, identity governance platforms, and enterprise monitoring solutions may need directory read or write access. In some cases a scoped admin role is appropriate.

The key distinction is scope and necessity. An app assigned Global Administrator when it only needs User.ReadWrite.All is over-privileged. An app assigned a role that was needed during initial setup but is no longer actively used should have that role removed.

Legitimate cases should be documented with a named owner, the specific automation the app supports, and a defined review schedule. App credentials should be managed through a secrets management process, not embedded in code or shared informally.

Before modifying any service principal's role assignment:

• Identify the specific Entra roles assigned to the application and confirm whether they are active
• Check whether the role assignment is directly assigned or inherited, and whether it is permanent or time-limited
• Review the app's sign-in and API activity logs to confirm whether the privileged access is still being used
• Check the app's credentials — are there active client secrets or certificates, and who has access to them?
• Confirm with the named owner or the team responsible for the app whether the role assignment is still required
• Check whether the app could function with a lower-privilege Graph API permission set instead of a directory role
• Review related Overe alerts or Defender signals associated with the service principal

1. Use Overe to review all service principals with Entra role assignments, prioritising Global Admin and other high-privilege roles
2. For roles that are no longer needed, remove the assignment immediately
3. For active apps, work with the owner to determine whether the role scope can be reduced
4. Where possible, replace directory role assignments with Graph API permissions scoped to the specific operations required
5. Rotate or expire client secrets for any app with a privileged role assignment, particularly if credentials have been long-lived
6. For apps with no identifiable owner, investigate activity logs before taking action
7. Consider enabling Privileged Identity Management (PIM) for service principals where available to restrict standing privileged access

Where direct remediation is required, Overe provides links to the appropriate Microsoft admin controls to complete the action safely.

Microsoft: Assign Entra roles to service principals - https://learn.microsoft.com/en-us/entra/identity/role-based-access-control/manage-roles-portal

Microsoft: Secure service principals in Microsoft Entra ID - https://learn.microsoft.com/en-us/entra/architecture/service-accounts-principal

Microsoft: Use PIM to secure privileged access - https://learn.microsoft.com/en-us/entra/id-governance/privileged-identity-management/pim-configure

• Apps with risky permissions
• Dormant apps
• Privileged role assignments without clear ownership
• Conditional Access exclusions creating risk