The Lost Update Problem
The Scenario: Bob wants to exploit an ATM with a race condition bug. You get to choose which update operation(s) the bank processes!
How to Play:
- Read Balance - Bank checks the account (starts at 1000 DKK)
- Bob Operations - Withdraw or deposit money (Bob gains cash, but bank hasn't updated yet)
- Update Balance - Choose only ONE operation for the bank to process
- Finish Transaction - Calculate Bob's profit and unlock achievements
Example Exploit: Bob withdraws 2 times (gaining 200 DKK cash), but only ONE withdrawal is applied to his account (losing 100 DKK). Bob's Net profit: 100 DKK! The bank loses: 100 DKK!
Tips:
- Hover over trophies to see requirements
- Swipe trophies to reset them
- Double-click trophies to replay
- Refresh page to reset balance (keeps achievements)
