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Pg_net Grants To Anon/Authenticated Cannot Be Revoked Due To Supabase_admin Ownership, Creating Latent SSRF Risk

Supabase projects default to granting EXECUTE on net.http_post/net.http_get and USAGE on net schema to anon/authenticated, but the net schema and functions are owned by supabase_admin. Project postgres role lacks grant option, so REVOKE commands silently no-op, leaving a privilege that could be exploited if the net schema is ever exposed via Data API.

highConfidence 85%Supabase

Origin Analysis

In PostgreSQL, only the object owner or a role with grant option can revoke privileges on an object. The pg_net extension creates the net schema and its functions as owned by supabase_admin. The project's postgres role is neither the owner nor a member of supabase_admin, and has no grant option on the existing grants, so REVOKE statements are accepted but have no effect (silent no-op).

1. Connect to Supabase SQL editor as postgres. 2. Run: REVOKE EXECUTE ON ALL FUNCTIONS IN SCHEMA net FROM anon, authenticated; 3. Run: REVOKE USAGE ON SCHEMA net FROM anon, authenticated; 4. Check: SELECT has_function_privilege('anon', 'net.http_post(text, jsonb, jsonb, integer)', 'EXECUTE'); Returns true, confirming revocation failed. 5. Check ownership: SELECT nspname, pg_get_userbyid(nspowner) FROM pg_namespace WHERE nspname='net'; Shows owner supabase_admin.

Fixing Code Block

0x7F 45 4C 46 02 01 01 000x90 12 AB 04 C1 7E 33 08
0xA4 1C 90 3E 77 0B D2 580x11 F6 6A 2C 80 19 DE 44
0x00 00 00 00 03 00 3E 000x01 00 B7 4D 55 90 0C 61
0x6C 69 62 63 2E 73 6F 2E0x36 00 8E 17 42 AA 05 F3
0xDE C0 DE 01 8B 45 FC 890xC7 5D 20 6F 91 03 E4 78
0x13 37 00 4F 9A 2D E1 700x08 B4 5C 22 71 D0 4A 16
0x48 8D 3D 22 01 00 00 E80x91 FF 0A 63 2E 57 B8 04
0x5A 91 C3 0E 44 70 1B 880x02 6F 39 C4 15 80 ED 27
0xFF 15 40 20 60 00 48 890xC3 90 7A 01 4C 28 B1 56
0x0F 1F 44 00 00 55 48 890xE5 C3 18 6D 92 0B 33 A7

Edge Case Audit

Revoking USAGE on the net schema will block any legitimate use of pg_net functions by anon/authenticated, including any application logic that calls net.http_* directly with the anon or authenticated role. Before applying, verify no application code depends on these roles having direct access. Rollback is straightforward: re-grant the privileges if needed. The change may be transient if a future pg_net extension upgrade re-applies default grants; monitor after upgrades. Concurrency: revoke is immediate and may cause in-flight queries using net functions to fail if they execute after revocation. Apply during a maintenance window.