Submitted by reassor, also found by cccz and cmichel
Function.buy buys the tokens for whatever price is set as tokenOutPrice. This might lead to accidental collisions or front-running attacks when user is trying to buy the tokens and his transaction is being included after the transaction of changing the price of the token via setTokenOutPrice.
Scenario:
Another variation of this attack can be performed using front-running.
Manual Review / VSCode
It is recommended to add additional parameter uint256 believedPrice to KnightingRound.buy function and check if believedPrice is equal to tokenOutPrice.
GalloDaSballo (BadgerDAO) confirmed 
