A gambling smart contract implementation for RuletkaIo, an Ethereum gambling game, generates a random value that is predictable by an external contract call. The developer wrote a random() function that uses a block timestamp and block hash from the Ethereum blockchain. This can be predicted by writing the same random function code in an exploit contract to determine the deadSeat value.

References

• https://nvd.nist.gov/vuln/detail/CVE-2018-17968
• https://github.com/TEAM-C4B/CVE-LIST/tree/master/CVE-2018-17968