Microsoft Entra ID Flaw Let Agent Admins Take Over Service Principals

Microsoft fixed a privilege escalation flaw in Entra ID that allowed users with the built-in Agent ID Administrator role to take over arbitrary service principals, including identities unrelated to AI agents. Silverfort reported that the role could assign ownership over a target service principal, add new credentials, and then authenticate as that principal, effectively enabling full service principal takeover. The weakness stemmed from a scoping gap in Microsoft’s Agent Identity Platform, where a role intended to manage agent-related objects could also affect standard directory components.

The exposure was especially serious in tenants with highly privileged service principals, where attackers could inherit sensitive API access, integrations, or directory-level roles and potentially reach Global Administrator-equivalent power. Silverfort said the abuse path was broadly relevant because most customer tenants it analyzed had at least one privileged service principal, while ownership changes could blend in with normal administrative activity and evade detection. Microsoft addressed the issue with a backend fix that restricted the Agent ID Administrator role to agent-related objects and said the remediation was fully rolled out by April 9.