Authorization Best Practices

What this best practices guide is

A practical guide to authorization for developers who build apps where users should only see and change some of the data. It covers deny by default and server-side checks, object-level authorization against IDOR and BOLA, choosing between RBAC, ABAC and ReBAC, multi-tenant isolation with row-level security, policy engines, admin and support access, auditing, and testing that permissions actually hold.

It has 7 chapters and 22 practices, each with why it matters, what to do and what to avoid. For developers who build apps with users and permissions.

Chapter by chapter

1. Deny by default, check on the server (3 practices)

The three rules every other practice builds on: nothing is allowed unless a rule says so, the check runs on the server for every request, and an error means no.

2. Object-level authorization: stop IDOR and BOLA (4 practices)

Checking that a user may call an endpoint is not enough. Each object they ask for, by ID, has to belong to something they may access.

3. Choosing a model: RBAC, ABAC and ReBAC (3 practices)

Roles, attributes and relationships each answer "may this user do this?" differently. Pick the one that matches how your product actually shares data.

4. Multi-tenant isolation (3 practices)

In a SaaS app, the worst authorization bug is one tenant seeing another tenant's data. Isolation has to hold in the database, the cache and every background job.

5. Policy engines, tokens and services (3 practices)

As an app grows, authorization logic moves out of controllers into one decision point. These practices keep that decision correct across services and tokens.

6. Admin access, support access and auditing (3 practices)

Admins and support staff can see the most data, so their access needs the most care: separate controls, time limits and a record of what they did.

7. Testing authorization (3 practices)

Permissions break silently: nothing crashes, the wrong person just sees the data. Automated tests are how you notice before they do.

How it works on Sefism

The guide reads like a short course: a syllabus, then one chapter per page in a focused reader, with a quiz at the end of each chapter for members. The opening chapters are open to everyone. Adding it to your account uses credits, opens every chapter and keeps your progress.

Every claim is checked against the sources listed on the page (8 cited).