Check for misconfigured public buckets

Deep scan public buckets for sensitive content

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 PUBLIC BUCKET SECURITY AUDIT
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 Project: abc123def.supabase.co

 ─────────────────────────────────────────────────────────
 Public Bucket Discovery
 ─────────────────────────────────────────────────────────

 Public Buckets Found: 3/5

 ─────────────────────────────────────────────────────────
 1. avatars ✅ APPROPRIATE
 ─────────────────────────────────────────────────────────

 Status: Public (Expected)
 Purpose: User profile pictures
 Content Analysis:
 ├── All files are images (jpg, png, webp)
 ├── No sensitive filenames detected
 ├── File sizes appropriate for avatars (< 1MB)
 └── No metadata concerns

 Assessment: This bucket appropriately contains only
             public user-facing content.

 ─────────────────────────────────────────────────────────
 2. uploads 🟠 P1 - NEEDS REVIEW
 ─────────────────────────────────────────────────────────

 Status: Public (Unexpected for this content)
 Purpose: User file uploads

 Content Analysis:
 ├── Mixed file types (PDF, DOC, images)
 ├── Some sensitive filenames detected
 └── Should likely be private with RLS

 Sensitive Content Indicators:
 ├── 12 files with 'invoice' in name
 ├── 8 files with 'contract' in name
 ├── 3 files with 'passport' in name
 └── 156 PDF files (may contain sensitive data)

 Risk Assessment:
 └── 🟠 User-uploaded content publicly accessible
     Anyone with filename can access any user's files

 Recommendation:
 ```sql
 -- Make bucket private
 UPDATE storage.buckets
 SET public = false
 WHERE name = 'uploads';

 -- Add user-specific RLS
 CREATE POLICY "Users access own uploads"
   ON storage.objects FOR ALL
   USING (
     bucket_id = 'uploads'
     AND auth.uid()::text = (storage.foldername(name))[1]
   );

## Bucket Classification

The skill classifies buckets by content:

| Classification | Criteria | Action |
|----------------|----------|--------|
| **Appropriate Public** | Profile images, public assets | None needed |
| **Needs Review** | User uploads, mixed content | Consider making private |
| **Critical Misconfiguration** | Backups, secrets, exports | Immediate remediation |

## Sensitive Content Patterns

### P0 - Critical (Never Public)

- `*.sql` - Database dumps
- `*.env*` - Environment files
- `*secret*`, `*credential*` - Secrets
- `*backup*` - Backup files
- `*export*` - Data exports

### P1 - High (Usually Private)

- `*invoice*`, `*payment*` - Financial
- `*contract*`, `*agreement*` - Legal
- `*passport*`, `*id*`, `*license*` - Identity
- User-uploaded documents

### P2 - Medium (Review Needed)

- Configuration files
- Log files
- Debug exports

## Context Output

```json
{
  "public_bucket_audit": {
    "timestamp": "2025-01-31T12:00:00Z",
    "public_buckets": 3,
    "findings": [
      {
        "bucket": "backups",
        "severity": "P0",
        "issue": "Database backups and secrets publicly accessible",
        "exposed_files": 45,
        "critical_files": [
          "db-backup-2025-01-30.sql",
          "secrets.env",
          ".env.production"
        ],
        "remediation": "Make bucket private immediately, rotate secrets"
      }
    ]
  }
}

-- Supabase creates buckets public by default in UI
-- Always verify and change to private if needed
UPDATE storage.buckets
SET public = false
WHERE name = 'new-bucket';

-- Only allow admin to create buckets
REVOKE INSERT ON storage.buckets FROM authenticated;
REVOKE INSERT ON storage.buckets FROM anon;

// Validate file type before upload
const allowedTypes = ['image/jpeg', 'image/png'];
if (!allowedTypes.includes(file.type)) {
  throw new Error('Invalid file type');
}

// Use user-specific paths
const path = `${user.id}/${file.name}`;
await supabase.storage.from('uploads').upload(path, file);

{
  "evidence_id": "STG-PUB-001",
  "timestamp": "2025-01-31T10:45:00Z",
  "category": "storage-audit",
  "type": "public_bucket_audit",
  "severity": "P0",

  "bucket": "backups",

  "public_url_test": {
    "url": "https://abc123def.supabase.co/storage/v1/object/public/backups/secrets.env",
    "curl_command": "curl -I 'https://abc123def.supabase.co/storage/v1/object/public/backups/secrets.env'",
    "response_status": 200,
    "content_type": "text/plain",
    "accessible": true
  },

  "assessment": {
    "classification": "critical_misconfiguration",
    "should_be_public": false,
    "contains_sensitive_data": true,
    "file_types_exposed": ["sql", "env", "csv"]
  },

  "remediation": {
    "immediate": "UPDATE storage.buckets SET public = false WHERE name = 'backups';",
    "secrets_to_rotate": ["All keys in secrets.env"],
    "incident_response": "Consider this a data breach"
  }
}