TwentyOne

Summary

If we take a look at the described rules, we have the following: "A player must deposit 1 ETH to play, with a maximum payout of 2 ETH upon winning."

Considering this fact, we can see a wrong validation in the function startGame(), where it's being validated if the player sent over or equals to 1 ether and then revert with an error.

Vulnerability Details

There is a wrong validation in the function startGame(), where it's being validated if the player sent over or equals to 1 ether and then revert with an error. We must check if the msg.value is equals to 1 ether and leave the player call start game.

Impact

Players can not start a game as if they send the correct amount described on the rules.

Tools Used

Foundry

Recommendations

We must check if the msg.value is equals to 1 ether and leave the player call start game instead of reverting if the amount is equals or over to 1 ether.

Example: