Broad SELECT for Authenticated Role

What “Broad SELECT for Authenticated Role” means (plain English)

Granting SELECT to the authenticated role without row filters makes the table accessible to anyone with an account.

How Broad SELECT for Authenticated Role works in Supabase/Postgres (technical)

Authenticated behaves like PUBLIC when there are no restrictive policies, so broad SELECT grants effectively turn the table into an open API.

Attack paths & failure modes for Broad SELECT for Authenticated Role

• Broad SELECT for Authenticated Role: direct API bypass: An API endpoint queried a table directly from the browser with authenticated SELECT permissions.
• Broad SELECT for Authenticated Role: migration drift regression: A new table or view added in a migration was granted SELECT to authenticated without row filters.
• Broad SELECT for Authenticated Role: direct API bypass: No row filters existed, so any logged-in user could enumerate sensitive rows through direct REST calls.
• Broad SELECT for Authenticated Role: migration drift regression: The grant turned the table into a public API for every logged-in user.
• The configuration doesn’t match what the UI implies (direct API access bypasses the app).
• Policies/grants drift over time and widen access without anyone noticing.
• Fixes are applied without verification, leading to false confidence.

Why Broad SELECT for Authenticated Role matters for Supabase security

It leaks data to every user and removes accountability for who accessed rows. If Broad SELECT for Authenticated Role remains unresolved, attackers can automate enumeration and unauthorized writes at API speed. Treat it as a production reliability risk as well as a data security risk, because incidents spread quickly once clients discover weak access boundaries.

Common Broad SELECT for Authenticated Role mistakes that lead to leaks

• Granting SELECT to authenticated for convenience.
• Not binding the policy to auth.uid() or tenant claims.
• Assuming the UI prevents abusive queries.
• Broad SELECT for Authenticated Role: direct API bypass: No row filters existed, so any logged-in user could enumerate sensitive rows through direct REST calls.
• Broad SELECT for Authenticated Role: migration drift regression: The grant turned the table into a public API for every logged-in user.

Where to look for Broad SELECT for Authenticated Role in Supabase

• Your grants, policies, and any direct client access paths.
• Storage and RPC settings (common blind spots).

How to detect Broad SELECT for Authenticated Role issues (signals + checks)

Use this as a quick checklist to validate your current state:

• Try the same queries your frontend can run (anon/authenticated). If sensitive rows come back, you have exposure.
• Verify RLS is enabled and (for sensitive tables) forced.
• List policies and look for conditions that don’t bind rows to a user or tenant.
• Audit grants to anon / authenticated on sensitive tables and functions.
• Broad SELECT for Authenticated Role: direct API bypass: Authenticated is not a security boundary.
• Broad SELECT for Authenticated Role: direct API bypass: Grants expose API surfaces even without UI links.
• Broad SELECT for Authenticated Role: direct API bypass: Backend feeds can redact and scope results safely.
• Re-test after every migration that touches security-critical tables or functions.

How to fix Broad SELECT for Authenticated Role (backend-only + zero-policy posture)

Mockly’s safest default is backend-only access: the browser should not query tables, call RPC, or access Storage directly.

1. Decide which operations must remain client-side (often: none for sensitive resources).
2. Create server endpoints (API routes or server actions) for required reads/writes.
3. Apply hardening SQL: enable+force RLS where relevant, remove broad policies, and revoke grants from client roles.
4. Generate signed URLs for private Storage downloads on the server only.
5. Re-run a scan and confirm the issue disappears.
6. Add a regression check to your release process so drift doesn’t reintroduce exposure. Fixes that worked in linked incidents:

• Broad SELECT for Authenticated Role: direct API bypass: Revoke the grant, return the feed via a backend endpoint, and verify direct queries fail.
• Broad SELECT for Authenticated Role: migration drift regression: Add restrictive policies or backend-only access and include grant checks in migration reviews.

Verification checklist for Broad SELECT for Authenticated Role

1. Attempt direct access using client credentials and confirm it fails.
2. Apply a backend-only fix pattern and verify end-to-end behavior.
3. Re-run a scan after changes and after the next migration.
4. Broad SELECT for Authenticated Role: direct API bypass: Authenticated is not a security boundary.
5. Broad SELECT for Authenticated Role: direct API bypass: Grants expose API surfaces even without UI links.
6. Broad SELECT for Authenticated Role: direct API bypass: Backend feeds can redact and scope results safely.
7. Broad SELECT for Authenticated Role: direct API bypass: Verify exposure with direct REST calls.
8. Broad SELECT for Authenticated Role: migration drift regression: Migrations can introduce exposures.

SQL sanity checks for Broad SELECT for Authenticated Role (optional, but high signal)

If you prefer evidence over intuition, run a small set of SQL checks after each fix.

The goal is not to memorize catalog tables — it’s to make sure the access boundary you intended is the one Postgres actually enforces:

• Confirm RLS is enabled (and forced where appropriate) for tables tied to this term.
• List policies and read them as plain language: who can do what, under what condition?
• Audit grants for anon/authenticated and PUBLIC on the tables, views, and functions involved.
• If Storage is involved: review bucket privacy and policies for listing/reads.
• If RPC is involved: review EXECUTE grants for functions and whether privileged functions are server-only.

Pair these checks with a direct API access test using client credentials. When both agree, you can ship the fix with confidence.

Over time, keep a small “query pack” for the checks you trust and run it after every migration. That’s how you prevent quiet regressions.

Prevent Broad SELECT for Authenticated Role drift (so it doesn’t come back)

• Add a repeatable checklist and re-run it after schema changes.
• Prefer backend-only access for sensitive resources.
• Keep one reusable verification test for “Broad SELECT for Authenticated Role: direct API bypass” and rerun it after every migration that touches this surface.
• Keep one reusable verification test for “Broad SELECT for Authenticated Role: migration drift regression” and rerun it after every migration that touches this surface.

Rollout plan for Broad SELECT for Authenticated Role fixes (without breaking production)

Many hardening changes fail because teams revoke direct access first and only later discover missing backend paths.

Use this sequence to reduce both risk and outage pressure:

1. Implement and verify the backend endpoint or server action before permission changes.
2. Switch clients to that backend path behind a feature flag when possible.
3. Then revoke direct client access (broad grants, permissive policies, public bucket reads, or broad EXECUTE).
4. Run direct-access denial tests and confirm authorized backend flows still succeed.
5. Re-scan after deployment and again after the next migration.

This turns security fixes into repeatable rollout mechanics instead of one-off emergency changes.

Incident breakdowns for Broad SELECT for Authenticated Role (real scenarios)

Broad SELECT for Authenticated Role: direct API bypass

Scenario: An API endpoint queried a table directly from the browser with authenticated SELECT permissions.

What failed: No row filters existed, so any logged-in user could enumerate sensitive rows through direct REST calls.

What fixed it: Revoke the grant, return the feed via a backend endpoint, and verify direct queries fail.

Why the fix worked: The backend enforces filters and logs access, while direct browser calls now get permission denied.

Key takeaways:

• Authenticated is not a security boundary.
• Grants expose API surfaces even without UI links.
• Backend feeds can redact and scope results safely.
• Verify exposure with direct REST calls.

Read full example: Broad SELECT for Authenticated Role: direct API bypass

Broad SELECT for Authenticated Role: migration drift regression

Scenario: A new table or view added in a migration was granted SELECT to authenticated without row filters.

What failed: The grant turned the table into a public API for every logged-in user.

What fixed it: Add restrictive policies or backend-only access and include grant checks in migration reviews.

Why the fix worked: Restricted policies prevent the exposure, and CI checks stop new tables from shipping as open surface areas.

Key takeaways:

• Migrations can introduce exposures.
• CI should validate grant changes.
• Document intended consumers for each table.
• Test direct API calls after every migration.

Read full example: Broad SELECT for Authenticated Role: migration drift regression

Real-world examples of Broad SELECT for Authenticated Role (and why they work)

• Broad SELECT for Authenticated Role: direct API bypass — Granting SELECT to authenticated let attackers bypass the UI.
• Broad SELECT for Authenticated Role: migration drift regression — A migration introduced a broad authenticated SELECT, creating a new leak.

Related terms

• Missing WITH CHECK Policy → /glossary/missing-with-check-policy
• Broad UPDATE for Authenticated Role → /glossary/broad-authenticated-update