examples
Default Function EXECUTE to PUBLIC examples
These examples show how Default Function EXECUTE to PUBLIC problems ship in real apps — and what fixes actually work when tested via direct API access.
Why Default Function EXECUTE to PUBLIC examples matter
Function privilege drift is easy to reintroduce through migrations. Locking down default EXECUTE prevents newly shipped routines from becoming instant attack surface and keeps RPC exposure intentional.
Examples about Default Function EXECUTE to PUBLIC
| Example | Summary | URL |
|---|---|---|
| Default Function EXECUTE to PUBLIC: direct API bypass | A production-like scenario where Default Function EXECUTE to PUBLIC is exploited through direct requests that bypass frontend assumptions. | /examples/default-function-execute-to-public/direct-api-bypass-default-function-execute-to-public |
| Default Function EXECUTE to PUBLIC: migration drift regression | A release regression where migration drift silently reintroduces default function execute to public after an earlier fix. | /examples/default-function-execute-to-public/migration-drift-default-function-execute-to-public |
Root cause → fix pattern analysis for Default Function EXECUTE to PUBLIC
Examples are most useful when you can translate them into a repeatable fix pattern. This table highlights the “why” behind each fix:
| Example | Root cause | Fix pattern | URL |
|---|---|---|---|
| Default Function EXECUTE to PUBLIC: direct API bypass | Security controls depended on frontend behavior and partial configuration checks. The underlying grants, schema exposure, or policy predicates still allowed direct access patterns that untrusted clients could reproduce. | The team removed direct sensitive paths from client reach, tightened role grants and policy predicates, and added endpoint-level verification tests that run in CI after each migration. | /examples/default-function-execute-to-public/direct-api-bypass-default-function-execute-to-public |
| Default Function EXECUTE to PUBLIC: migration drift regression | Migrations were treated as schema-only changes without mandatory security gates. No automated checks validated grants, exposed schema settings, or authorization behavior before deployment. | The team added migration-time policy/grant diff checks, blocked deploys on drift findings, and required post-deploy direct-access verification for each changed surface. | /examples/default-function-execute-to-public/migration-drift-default-function-execute-to-public |
How Default Function EXECUTE to PUBLIC failures typically happen
- Revoking EXECUTE on existing routines once, but not setting default privileges for future migrations.
- Assuming function names are obscure enough to protect them from discovery or invocation.
- Exposing admin-like routines in schemas reachable by client credentials.
Fix patterns that tend to work for Default Function EXECUTE to PUBLIC
Across these examples, the highest-leverage fixes share a theme: remove direct client access and make verification repeatable.
- Backend-only access for sensitive operations (server endpoints enforce authorization).
- Least-privilege grants: revoke broad privileges from anon/authenticated.
- Small, testable policies if you intentionally keep client access — avoid complex conditions.
- A verification step that proves direct access fails (not just that the UI hides data).
How to spot Default Function EXECUTE to PUBLIC in your own project (signals)
- A direct API call returns rows/files even when the UI is supposed to restrict them.
- RLS/policies exist, but access still succeeds (often because RLS is disabled or policies are too broad).
- Permissions depend on the client behaving “nicely” (UI checks) rather than the database enforcing access.
- After a migration, access behavior changes unexpectedly (drift).
How to use these examples to fix your own app
- Match the scenario to your table/bucket/function setup.
- Identify the root cause (not just the symptom).
- Apply the relevant template or conversion guide.
- Verify direct access fails for client credentials.
- Document the rule so it doesn’t regress.
Verification checklist for Default Function EXECUTE to PUBLIC fixes
- Reproduce the issue once using direct API access (anon/authenticated) so you know it’s real.
- Apply the fix pattern (backend-only access + least privilege) using a template.
- Repeat the same direct access call and confirm it now fails.
- Confirm the app still works via backend endpoints for authorized users.
- Re-scan after the fix and add a drift guard for the next migration.
Preventing Default Function EXECUTE to PUBLIC regressions (drift guard)
- Re-run the same direct access test after every migration that touches auth, policies, grants, Storage, or functions.
- Keep a short inventory of sensitive resources and treat them as server-only by default.
- Review new tables/buckets/functions in code review with an access-control checklist.
- If you intentionally allow client access, document the policy rationale and add tests for it.
Optional SQL checks for Default Function EXECUTE to PUBLIC (extra confidence)
If you like having a repeatable “proof”, add a small set of SQL checks to your process.
- Confirm RLS status for tables involved (enabled/forced where appropriate).
- List policies and read them as plain language: who can do what under what condition?
- Audit grants to anon/authenticated and PUBLIC for tables, views, and functions tied to this topic.
- If Storage/RPC is involved, explicitly audit bucket settings and EXECUTE grants.
These checks complement (not replace) the direct access tests shown in the examples.
Decision guide for Default Function EXECUTE to PUBLIC: template vs conversion vs integration
If you’re here because you found this topic in a scan, the fastest path depends on whether the fix is a small config change or a workflow change.
- Choose a template when you need a copy/paste change plus verification (tighten a policy/grant/bucket setting).
- Choose a conversion when you need to change an access model end-to-end (unsafe → backend-only) with example transformations.
- Choose an integration when the fix is a workflow pattern you’ll repeat (signed URLs, server-only RPC, backend endpoints).
If you’re unsure, start with the smallest template that removes direct client access, then add integrations for durability.
Evidence to keep after fixing Default Function EXECUTE to PUBLIC (makes reviews faster)
Teams often “fix” a topic but can’t prove it later. Save a few small artifacts so you can re-verify after migrations:
- The direct access request you used before the fix (and the expected denial after).
- A short boundary statement (who can access what, through which server endpoint).
- The change you applied (policy/grant/bucket setting/EXECUTE revoke) and why.
- The drift guard you’ll run after migrations (scan, checklist query, or release checklist item).
Related pages
- Glossary: Default Function EXECUTE to PUBLIC →
/glossary/default-function-execute-to-public - Template: Lock down RPC: revoke EXECUTE from public roles →
/templates/rpc-functions/lock-down-rpc-execute
What to do after you fix one example (so it stays fixed)
One fixed example is great — but the real win is preventing drift.
- Write a one-sentence boundary statement (who can access what, through which server path).
- Keep the one direct access test you used before the fix (and expect it to fail after).
- Re-run the same test after migrations that touch policies, grants, buckets, or functions.
If you can re-run the test and it still fails, you’ve turned a one-time fix into a durable control.
FAQ
What’s the fastest fix pattern when Default Function EXECUTE to PUBLIC shows up in a scan?
Prefer backend-only access and remove direct client privileges. Then add verification checks that prove direct access fails.
Can I fix Default Function EXECUTE to PUBLIC with policies alone?
Sometimes, but it’s easy to get subtly wrong. Use these examples to learn the failure modes, and verify with direct API tests.
How do I choose between examples, templates, and conversions?
Examples explain the pattern, templates show concrete implementation, and conversions describe the whole transformation from unsafe to safe.
Next step
Want to know if your project matches any of these scenarios? Run a Mockly scan and compare your findings to the examples here.