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.
Severity
CVSS 3.0
7.5 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
0.9% chance of exploitation in the next 30 days; higher than 60% of CVEs (scores of 2026-10-31)