supabase-audit-buckets-list

name	supabase-audit-buckets-list
description	List all storage buckets and their configuration to identify the storage attack surface.

List Storage Buckets

🔴 CRITICAL: PROGRESSIVE FILE UPDATES REQUIRED

You MUST write to context files AS YOU GO, not just at the end.

• Write to .sb-pentest-context.json IMMEDIATELY after each bucket discovered
• Log to .sb-pentest-audit.log BEFORE and AFTER each operation
• DO NOT wait until the skill completes to update files
• If the skill crashes or is interrupted, all prior findings must already be saved

This is not optional. Failure to write progressively is a critical error.

This skill discovers all storage buckets configured in a Supabase project.

When to Use This Skill

• To inventory all storage buckets
• Before testing bucket access permissions
• To identify publicly accessible buckets
• As part of storage security audit

Prerequisites

• Supabase URL and anon key available
• Detection completed

Understanding Supabase Storage

Supabase Storage provides:

https://[project].supabase.co/storage/v1/

Buckets can be:

• Public: Files accessible without authentication
• Private: Files require authentication and RLS policies

Storage API Endpoints

Endpoint	Purpose
/storage/v1/bucket	List buckets
/storage/v1/object/list/[bucket]	List files in bucket
/storage/v1/object/[bucket]/[path]	Access file
/storage/v1/object/public/[bucket]/[path]	Public file URL

Usage

Basic Bucket List

List storage buckets on my Supabase project

With Configuration Details

List all buckets with their security settings

Output Format

═══════════════════════════════════════════════════════════
 STORAGE BUCKETS
═══════════════════════════════════════════════════════════

 Project: abc123def.supabase.co
 Buckets Found: 5

 ─────────────────────────────────────────────────────────
 Bucket Inventory
 ─────────────────────────────────────────────────────────

 1. avatars
    ├── Public: ✅ YES
    ├── File Size Limit: 1MB
    ├── Allowed MIME: image/jpeg, image/png, image/webp
    ├── Files (estimated): 1,247
    └── Status: ℹ️ Expected public bucket

    Public URLs pattern:
    https://abc123def.supabase.co/storage/v1/object/public/avatars/[filename]

 2. documents
    ├── Public: ❌ NO (Private)
    ├── File Size Limit: 50MB
    ├── Allowed MIME: application/pdf, application/msword, *
    ├── Files (estimated): 523
    └── Status: ✅ Private, needs RLS verification

 3. uploads
    ├── Public: ✅ YES
    ├── File Size Limit: 100MB
    ├── Allowed MIME: */* (ANY)
    ├── Files (estimated): 3,891
    └── Status: 🟠 P1 - Public with unrestricted MIME types

    Risk: Any file type can be uploaded and accessed
    Recommendation: Restrict allowed MIME types

 4. backups
    ├── Public: ✅ YES ← UNEXPECTED
    ├── File Size Limit: 500MB
    ├── Allowed MIME: */*
    ├── Files (estimated): 45
    └── Status: 🔴 P0 - Sensitive bucket is PUBLIC

    Risk: Backup files publicly accessible!
    Immediate Action: Change to private bucket

 5. temp
    ├── Public: ❌ NO
    ├── File Size Limit: 10MB
    ├── Allowed MIME: */*
    ├── Files (estimated): 12
    └── Status: ✅ Private temporary storage

 ─────────────────────────────────────────────────────────
 Summary
 ─────────────────────────────────────────────────────────

 Total Buckets: 5
 Public Buckets: 3
   ├── Expected Public: 1 (avatars)
   ├── P1 Issues: 1 (uploads - unrestricted MIME)
   └── P0 Critical: 1 (backups - should be private)

 Private Buckets: 2
   └── Need RLS verification with supabase-audit-buckets-read

 Next Steps:
 ├── Fix 'backups' bucket - make private immediately
 ├── Restrict MIME types on 'uploads' bucket
 ├── Test RLS on private buckets
 └── Verify no sensitive files in public buckets

═══════════════════════════════════════════════════════════

Bucket Configuration Analysis

Config	Good	Bad
public: false	✅ Private by default	❌ public: true for sensitive data
fileSizeLimit	✅ Appropriate limits	❌ No limit or very large
allowedMimeTypes	✅ Restricted list	❌ */* allows anything

Context Output

{
  "storage": {
    "buckets": [
      {
        "name": "avatars",
        "public": true,
        "file_size_limit": 1048576,
        "allowed_mime_types": ["image/jpeg", "image/png", "image/webp"],
        "estimated_files": 1247,
        "risk_level": "info",
        "expected_public": true
      },
      {
        "name": "backups",
        "public": true,
        "file_size_limit": 524288000,
        "allowed_mime_types": ["*/*"],
        "estimated_files": 45,
        "risk_level": "P0",
        "finding": "Sensitive bucket publicly accessible"
      }
    ],
    "summary": {
      "total": 5,
      "public": 3,
      "private": 2,
      "p0_issues": 1,
      "p1_issues": 1
    }
  }
}

Security Recommendations

For Public Buckets

-- Create restrictive RLS policy even for public buckets
CREATE POLICY "Public read avatars"
  ON storage.objects FOR SELECT
  USING (bucket_id = 'avatars');

CREATE POLICY "Users upload own avatar"
  ON storage.objects FOR INSERT
  WITH CHECK (
    bucket_id = 'avatars'
    AND auth.uid()::text = (storage.foldername(name))[1]
  );

For Private Buckets

-- Only owners can access their files
CREATE POLICY "Users access own documents"
  ON storage.objects FOR ALL
  USING (
    bucket_id = 'documents'
    AND auth.uid()::text = (storage.foldername(name))[1]
  );

Fix Public Backup Bucket

-- Make bucket private
UPDATE storage.buckets
SET public = false
WHERE name = 'backups';

-- Add strict RLS
CREATE POLICY "Only admins access backups"
  ON storage.objects FOR ALL
  USING (
    bucket_id = 'backups'
    AND (SELECT is_admin FROM profiles WHERE id = auth.uid())
  );

Common Issues

❌ Problem: Cannot list buckets ✅ Solution: Storage API may be restricted. This is actually good security. Note as "unable to enumerate."

❌ Problem: Many buckets found ✅ Solution: Large applications may have many. Focus on public buckets first.

❌ Problem: Bucket count doesn't match expected ✅ Solution: Some buckets may be created dynamically. Check application code.

MANDATORY: Progressive Context File Updates

⚠️ This skill MUST update tracking files PROGRESSIVELY during execution, NOT just at the end.

Critical Rule: Write As You Go

DO NOT batch all writes at the end. Instead:

1. Before starting bucket enumeration → Log the action to .sb-pentest-audit.log
2. After each bucket discovered → Immediately update .sb-pentest-context.json
3. After each configuration analyzed → Log the result

This ensures that if the skill is interrupted, crashes, or times out, all findings up to that point are preserved.

Required Actions (Progressive)

1. Update .sb-pentest-context.json with results:

   {
     "storage": {
       "buckets": [ ... ],
       "summary": { "total": 5, "public": 3, "private": 2 }
     }
   }
   

2. Log to .sb-pentest-audit.log:

   [TIMESTAMP] [supabase-audit-buckets-list] [START] Listing storage buckets
   [TIMESTAMP] [supabase-audit-buckets-list] [SUCCESS] Found 5 buckets
   [TIMESTAMP] [supabase-audit-buckets-list] [CONTEXT_UPDATED] .sb-pentest-context.json updated
   

3. If files don't exist, create them before writing.

FAILURE TO UPDATE CONTEXT FILES IS NOT ACCEPTABLE.

MANDATORY: Evidence Collection

📁 Evidence Directory: .sb-pentest-evidence/04-storage-audit/

Evidence Files to Create

File	Content
buckets-config.json	All bucket configurations
buckets/[name]/file-list.json	File listing per bucket

Evidence Format

{
  "evidence_id": "STG-LIST-001",
  "timestamp": "2025-01-31T10:35:00Z",
  "category": "storage-audit",
  "type": "bucket_enumeration",

  "request": {
    "method": "GET",
    "url": "https://abc123def.supabase.co/storage/v1/bucket",
    "curl_command": "curl -s '$URL/storage/v1/bucket' -H 'apikey: $ANON_KEY' -H 'Authorization: Bearer $ANON_KEY'"
  },

  "buckets": [
    {
      "name": "avatars",
      "public": true,
      "file_size_limit": 1048576,
      "allowed_mime_types": ["image/jpeg", "image/png"],
      "risk_level": "info",
      "assessment": "Appropriate for public avatars"
    },
    {
      "name": "backups",
      "public": true,
      "file_size_limit": 524288000,
      "allowed_mime_types": ["*/*"],
      "risk_level": "P0",
      "assessment": "CRITICAL: Backup bucket should not be public"
    }
  ],

  "summary": {
    "total_buckets": 5,
    "public_buckets": 3,
    "private_buckets": 2,
    "critical_misconfigurations": 1
  }
}

Add to curl-commands.sh

# === STORAGE BUCKET ENUMERATION ===
# List all buckets
curl -s "$SUPABASE_URL/storage/v1/bucket" \
  -H "apikey: $ANON_KEY" \
  -H "Authorization: Bearer $ANON_KEY"

# List files in specific bucket
curl -s "$SUPABASE_URL/storage/v1/object/list/backups" \
  -H "apikey: $ANON_KEY" \
  -H "Authorization: Bearer $ANON_KEY"

Related Skills

• supabase-audit-buckets-read — Attempt to read files
• supabase-audit-buckets-public — Find misconfigured public buckets
• supabase-audit-storage-rls — Test storage RLS policies