FFGame gambling DApp suffered exploitation via mirrored-randomness vulnerability in November 2018. Attackers predicted the random outcome by leveraging information from earlier blockchain blocks. The attack was part of a coordinated assault on eight EOS gambling platforms using randomness prediction vectors.

By deploying the attack contract and using the same algorithm as FFgame to calculate the random number in the contract, the attacker immediately uses the random number attack contract in inline_action after generating the random number, resulting in the winning result being "predicted", thus reaching the super high winning rate.