CVE-2021-35041

The blockchain node in FISCO-BCOS V2.7.2 may have a bug when dealing with unformatted packet and lead to a crash. A malicious node can send a packet continuously. The packet is in an incorrect format and cannot be decoded by the node correctly. As a result, the node may consume the memory sustainably and crash. More details are shown at: https://github.com/FISCO-BCOS/FISCO-BCOS/issues/1951