Damn Vulnerable Bank Android Application aims to provide an interface for everyone to get a detailed understanding with internals and security aspects of android application.

How to Use Application

• Clone the repository and run the Backend Server as per instructions in the link.
• We have released the Apk so after downloading install it via adb or manual.
• After Installation open the App and add Backend IP in Homescreen
• Test running status by pressing health check
• Now create an account by signup option and then login with your credentials
• Now you can see the dashboard and perform banking operations
• Login as admin to approve beneficiary
• The database is pre-populated with a few users for quick exploration.

Username	Password	Account Number	Beneficiaries	Admin privileges
user1	password1	111111	222222, 333333, 444444	No
user2	password2	222222	None	No
user3	password3	333333	None	No
user4	password4	444444	None	No
admin	admin	999999	None	Yes

Features

• Sign up
• Login
• My profile interface
• Change password
• Settings interface to update backend URL
• Add fingerprint check before transferring/viewing funds
• Add pin check before transferring/viewing funds
• View balance
• Transfer money
  • Via manual entry
  • Via QR scan
• Add beneficiary
• Delete beneficiary
• View beneficiary
• View transactions history
• Download transactions history

Building the Apk with Obfuscation

• Go to Build options and select Generate Signed Bundled/Apk
• Then select Apk as option and click next
• Now we need a keystore to sign an apk
• Create a new keystore and remember its password
• After creating select that keystore and enter password
• Now select Build variant as Release and signature version as V2
• Now we can build the apk successfully

List of vulnerabilities in the application

To keep things crisp and interesting, we hidden this section. Do not toggle this button if you want a fun and challenging experience. Try to explore the application, find all the possible vulnerabilities and then cross check your findings with this list.

Spoiler Alert

• Root and emulator detection
• Anti-debugging checks (prevents hooking with frida, jdb, etc)
• SSL pinning - pin the certificate/public key
• Obfuscate the entire code
• Encrypt all requests and responses
• Hardcoded sensitive information
• Logcat leakage
• Insecure storage (saved credit card numbers maybe)
• Exported activities
• JWT token
• Webview integration
• Deep links
• IDOR

Backend to-do

• Add profile and change-password routes
• Create different secrets for admin and other users
• Add dynamic generation of secrets to verify JWT tokens
• Introduce bug in jwt verification
• Find a way to store database and mount it while using docker
• Dockerize environment

Authors

Thanks to these amazing people

Rewanth Cool (Rest API)	Github	LinkedIn
Hrushikesh Kakade (Android App)	Github	LinkedIn
Akshansh Jaiswal (Android App)	Github	LinkedIn