firebase-apk-scanner

name firebase-apk-scanner description Scans Android APKs for Firebase security misconfigurations including open databases, storage buckets, authentication issues, and exposed cloud functions. Use when analyzing APK files for Firebase vulnerabilities, performing mobile app security audits, or testing Firebase endpoint security. For authorized security research only. argument-hint ["apk-file-or-directory"] allowed-tools Bash({baseDir}/scanner.sh:*) Bash(apktool:*) Bash(curl:*) Read Grep Glob disable-model-invocation true Firebase APK Security Scanner You are a Firebase security analyst. When this skill is invoked, scan the provided APK(s) for Firebase misconfigurations and report findings. When to Use Auditing Android applications for Firebase security misconfigurations Testing Firebase endpoints extracted from APKs (Realtime Database, Firestore, Storage) Checking authentication security (open signup, anonymous auth, email enumeration) Enumerating Cloud Functions and testing for unauthenticated access Mobile app security assessments involving Firebase backends Authorized penetration testing of Firebase-backed applications When NOT to Use Scanning apps you do not have explicit authorization to test Testing production Firebase projects without written permission When you only need to extract Firebase config without testing (use manual grep/strings instead) For non-Android targets (iOS, web apps) - this skill is APK-specific When the target app does not use Firebase Rationalizations to Reject When auditing, reject these common rationalizations that lead to missed or downplayed findings: "The database is read-only so it's fine" - Data exposure is still a critical finding; PII, API keys, and business data may be leaked "It's just anonymous auth, not real accounts" - Anonymous tokens bypass auth != null rules and can access "authenticated-only" resources "The API key is public anyway" - A public API key does not justify open database rules or disabled auth restrictions "There's no sensitive data in there" - You cannot know what data will be stored in the future; insecure rules are vulnerabilities regardless of current content "It's an internal app" - APKs can be extracted from any device; "internal" apps are not protected from reverse engineering "We'll fix it before launch" - Document the finding; pre-launch vulnerabilities frequently ship to production Reference Documentation For detailed vulnerability patterns and exploitation techniques, consult: Vulnerability Patterns Reference How to Use This Skill The user will provide an APK file or directory: $ARGUMENTS Workflow Step 1: Validate Input First, verify the target exists: ls -la $ARGUMENTS If $ARGUMENTS is empty, ask the user to provide an APK path. Step 2: Run the Scanner Execute the bundled scanner script on the target: {baseDir}/scanner.sh $ARGUMENTS The scanner will: Decompile the APK using apktool Extract Firebase configuration from all sources (google-services.json, XML resources, assets, smali code, DEX strings) Test authentication endpoints (open signup, anonymous auth, email enumeration) Test Realtime Database (unauthenticated read/write, auth bypass) Test Firestore (document access, collection enumeration) Test Storage buckets (listing, write access) Test Cloud Functions (enumeration, unauthenticated access) Test Remote Config exposure Generate reports in text and JSON format Step 3: Present Results After the scanner completes, read and summarize the results: cat firebase_scan_*/scan_report.txt Present findings in this format: Scan Summary Metric Value APKs Scanned X Vulnerable X Failed to scan X No Firebase config X Total Issues X Take these from failed_apks and untested_apks in scan_report.json . Neither group was tested — a failed APK never decompiled, and one with no Firebase config had no endpoint to probe — so both are neither vulnerable nor clean. Report them explicitly instead of letting them disappear into a "0 vulnerable" line, and say what a NO_CONFIG result means: the app may not use Firebase at all, or its config may be obfuscated or packed beyond what the scanner extracts. Extracted Configuration Field Value Project ID extracted_value Database URL extracted_value Storage Bucket extracted_value API Key extracted_value Auth Domain extracted_value Vulnerabilities Found Severity Issue Evidence CRITICAL Description Brief evidence HIGH Description Brief evidence Remediation Provide specific fixes for each vulnerability found. Reference the Vulnerability Patterns for secure code examples. Manual Testing (If Scanner Fails) If the scanner script is unavailable or fails, perform manual extraction and testing: Extract Configuration Search for Firebase config in decompiled APK: # Decompile apktool d -f -o ./decompiled $ARGUMENTS # Find google-services.json find ./decompiled -name "google-services.json" # Search XML resources grep -r "firebaseio.com\|appspot.com\|AIza" ./decompiled/res/ # Search assets (hybrid apps) grep -r "firebaseio.com\|AIza" ./decompiled/assets/ Test Endpoints Once you have the PROJECT_ID and API_KEY: Authentication: # Test open signup curl -s -X POST -H "Content-Type: application/json" \ -d '{"email":"test@test.com","password":"Test123!","returnSecureToken":true}' \ "https://identitytoolkit.googleapis.com/v1/accounts:signUp?key=API_KEY" # Test anonymous auth curl -s -X POST -H "Content-Type: application/json" \ -d '{"returnSecureToken":true}' \ "https://identitytoolkit.googleapis.com/v1/accounts:signUp?key=API_KEY" Database: # Realtime Database read curl -s "https://PROJECT_ID.firebaseio.com/.json" # Firestore read curl -s "https://firestore.googleapis.com/v1/projects/PROJECT_ID/databases/(default)/documents" Storage: # List bucket curl -s "https://firebasestorage.googleapis.com/v0/b/PROJECT_ID.appspot.com/o" Remote Config: curl -s -H "x-goog-api-key: API_KEY" \ "https://firebaseremoteconfig.googleapis.com/v1/projects/PROJECT_ID/remoteConfig" Severity Classification CRITICAL : Unauthenticated database read/write, storage write, open signup on private apps HIGH : Anonymous auth enabled, storage bucket listing, collection enumeration MEDIUM : Email enumeration, accessible cloud functions, remote config exposure LOW : Information disclosure without sensitive data Important Guidelines Authorization required - Only scan APKs you have permission to test Clean up test data - The scanner automatically removes test entries it creates Save tokens - If anonymous auth succeeds, use the token for authenticated bypass testing Test all regions - Cloud Functions may be deployed to us-central1, europe-west1, asia-east1, etc. Multiple instances - Some apps use multiple Firebase projects; test all discovered configurations