FTX was attacked by Gas theft, hackers minted XEN tokens 17,000 times at zero cost

Opang and X-explore wrote that FTX was attacked by Gas theft, and hackers minted XEN tokens 17,000 times at zero cost. The FTX exchange lost a total of more than 81ETH due to the Gas stealing vulnerability, and the hacker address has obtained more than 100 million XEN tokens. According to the vulnerability analysis, FTX withdraws coins without handling fees, which brings great convenience to attackers for zero-cost theft. FTX does not impose any restrictions on the recipient address being the contract address, nor does it restrict the transfer Gas Limit of the ETH native Token, but uses the estimateGas method to evaluate the handling fee. This method results in most of the GAS LIMIT being 500,000, which exceeds the default value of 21,000 24 times.