The _addguess function of a simplelottery smart contract implementation for 1000 Guess, an Ethereum gambling game, generates a random value with publicly…

The _addguess function of a simplelottery smart contract implementation for 1000 Guess, an Ethereum gambling game, generates a random value with publicly readable variables such as the current block information and a private variable (which can be read with a getStorageAt call). Therefore, it allows attackers to always win and get rewards.