CVE-2018-17987
The determineWinner function of a smart contract implementation for HashHeroes Tiles, an Ethereum game, uses a certain blockhash value in an attempt to generate a random number for the case where NUM_TILES equals the number of people who purchased a tile, which allows an attacker to control the awarding of the prize by being the last person to purchase a tile.
Source: CVE-2018-17987