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Improper Input Validation II

rest-api-security | Level: Easy  | Total Lab Runs: 0 | Premium Lab

Lab Scoreboard

Lab Walkthrough Video:


A bank application allows users to query their account balance and the admin user has the capability to modify the account balance of any user. The bank application makes use of JWT tokens for authorization purposes.

The developers have recently released a feature to allow users to transfer money to an account (using the recipient's email id) but they forgot to place input validation checks on the transferred amount.

Note: Once the account balance exceeds $5000, the user gets a Golden Ticket.

Objective: Leverage the issue to increase the balance and get the Golden Ticket.

User Information:

Name
Jake
Emailjake@dummybank.com
Password
s1mpl3p@ssw0rd


Information of Jake's friend:

Name
Bob
Email
bob@dummybank.com


API Endpoints:

Endpoint
Description
Method
Parameter(s)
/balance
Read the balance of an account
GET
email, token
/balance
Modify the account balance
POSTemail, token, balance
/goldenticket
Get the Golden Ticket from the Bank API
POSTtoken

Instructions:

  • This lab is dedicated to you! No other users are on this network :)
  • Once you start the lab, you will have access to a Kali GUI instance.
  • Your Kali instance has an interface with IP address 192.X.Y.2. Run "ifconfig" to know the values of X and Y.
  • The bank application should be running on port 5000 on the machine located at the IP address 192.X.Y.3.
  • Do not attack the gateway located at IP address 192.X.Y.1


Verify:
1. Golden Ticket
 

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