The hook
Securing a Supabase project requires a multi-layered approach focusing on API key management, database security, and storage permissions. [S1] Improperly configured Row Level Security (RLS) or exposed sensitive keys can lead to significant data exposure incidents. [S2] [S3]
What changed
This research consolidates core security controls for Supabase environments based on official architecture guidelines. [S1] It focuses on the transition from default development configurations to production-hardened postures, specifically regarding access control mechanisms. [S2] [S3]
Who is affected
Applications utilizing Supabase as a Backend-as-a-Service (BaaS) are affected, particularly those that handle user-specific data or private assets. [S2] Developers who include the service_role key in client-side bundles or fail to enable RLS are at high risk. [S1]
How the issue works
Supabase leverages PostgreSQL's Row Level Security to restrict data access. [S2] By default, if RLS is not enabled on a table, any user with the anon key—which is often public—can access all records. [S1] Similarly, Supabase Storage requires explicit policies to define which users or roles can perform operations on file buckets. [S3]
What an attacker gets
An attacker possessing a public API key can exploit tables missing RLS to read, modify, or delete data belonging to other users. [S1] [S2] Unauthorized access to storage buckets can lead to the exposure of private user files or the deletion of critical application assets. [S3]
How FixVibe tests for it
FixVibe now covers this as part of its Supabase checks. baas.supabase-security-checklist-backfill reviews public Supabase Storage bucket metadata, anonymous object-listing exposure, sensitive bucket naming, and anon-bound Storage signals from the public anon boundary. Related live checks inspect service-role key exposure, Supabase REST/RLS posture, and repository SQL migrations for missing RLS.
What to fix
Always enable Row Level Security on database tables and implement granular policies for authenticated users. [S2] Ensure that only the 'anon' key is used in client-side code, while the 'service_role' key remains on the server. [S1] Configure Storage Access Control to ensure that file buckets are private by default and access is granted only through defined security policies. [S3]