Research by PeckShield security personnel found that due to a certain flaw in the Ethereum Parity client, when it receives a problem block, the next legal block with the same hash will not be processed. Specifically: An attacker can send a legitimate header + illegal body to the Parity client, so that the subsequent legal block header + body is filtered by the Partiy client, but can be received by clients such as geth, which may cause the Ethereum mainnet to be unexpected. Fork. " The Parity client currently accounts for 22.08% of the Ethereum mainnet and is mainly used in mining pools, exchanges and other related nodes. PeckShield security personnel suggest that mining pools and exchange nodes should migrate nodes to geth clients as soon as possible, and at the same time, they should appropriately increase the number of block confirmation blocks.