Delegated Permission Model is an access model where a user or application can act on behalf of another identity with explicitly granted scopes. The delegated party gets limited rights, usually through consent or token-based delegation, rather than the target account’s full permissions.
How Delegated Permission Models Work
A delegated permission model lets one identity perform actions for another, but only inside the explicit scope that has been granted. It is a boundary-setting mechanism, not a transfer of the target account’s full authority.
That distinction matters because the delegated party is operating through consent, token claims, or a similar authorisation grant. Good implementations make the acting identity, the resource owner, the granted scope, and the audience of the token visible and testable.
Why Delegated Permission Is Safer Than Full Impersonation
Delegation is meant to reduce blast radius. Instead of handing over the target identity’s complete permissions, the system issues constrained rights that should map to a narrow task, a specific API, or a limited duration.
When delegation is designed well, it supports least privilege and makes cross-user or cross-application workflows possible without broad credential sharing. That is why scope design, consent boundaries, and audience restriction are central to the model. OAuth Scope Design Guide
Common Failure Modes in Delegation
Delegated access becomes risky when scopes are too broad, consent is granted without sufficient scrutiny, or applications can retain long-lived access after the original need has passed. Those failures turn a narrow delegation into a durable foothold.
Another common weakness is confusing delegated permission with application permission or full impersonation. If engineers or admins treat “can act on behalf of” as if it were “can do anything the user can do,” they create overreach that is hard to detect later. Entra ID Applications and Consent Guide
For modern workflows, the same pattern also appears in autonomous software. When an agent acts for a human or another service, the permission boundary must still be explicit, narrow, and reviewable. AI Agent Authorisation Guide
Delegated Permissions in Practice
Practitioners should treat delegated permission as an authorisation design problem, not just an app-registration detail. The key question is whether the delegated scope is the minimum needed for the workflow and whether that scope is enforced consistently at runtime.
That usually means checking how consent is granted, how scopes are named, whether the delegation can be reviewed later, and whether the application can be revoked without breaking unrelated service flows. Where delegated access is embedded in cloud or directory platforms, it should be reviewed alongside privilege management and session controls. Authorisation Models Guide
For privilege-heavy environments, delegated permission should be aligned with temporary access and explicit approval, not left as a standing entitlement. Privileged Access Management Guide Just-in-Time Access and Zero Standing Privilege Guide
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP API Security Top 10 addresses the attack and risk surface, while NIST SP 800-53 Rev 5 sets the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | Delegated permission depends on controlled token and secret lifecycle for access delegation. |
| AC-3 — Access Enforcement | Delegated scopes are enforced access rules that limit what the acting identity can do. | |
| AC-6 — Least Privilege | Delegated permission is a least-privilege control that should constrain acting authority. | |
| Recommendation — Manage delegated tokens carefully, including issuance, rotation, revocation and expiration. Enforce delegated rights at the resource boundary and deny actions outside approved scope. Limit delegated access to the minimum rights required for the specific workflow. | ||
| OWASP API Security Top 10 | API5 — Broken Function Level Authorization | Delegated models fail when an API allows functions beyond the caller's delegated scope. |
| API1 — Broken Object Level Authorization | Delegated access must not expose objects outside the granted scope or owner context. | |
| Recommendation — Verify that every privileged function checks delegated authority before execution. Check object-level access for every request made under delegated authority. | ||