CVE-2018-12703: BLOCK18

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

The approveAndCallcode function of a smart contract implementation for Block 18 (18T), an tradable Ethereum ERC20 token, allows attackers to steal assets (e.g., transfer the contract's balances into their account) because the callcode (i.e., _spender.call(_extraData)) is not verified, aka the "evilReflex" issue. NOTE: a PeckShield disclosure states "some researchers have independently discussed the mechanism of such vulnerability."

Affected products

• BLOCK18 BLOCK18: any version

Published 2018-06-25. Last modified 2026-06-17.