The Ethereum Domain Name System ENS disclosed details of the vulnerabilities discovered by independent security researcher Sam Sun, and ENS had already migrated the original LLL contract to the new Solidity contract as of the end of January, and fixed the vulnerability. It is reported that if the ENS domain name holder performs the registration in a special way, then even if the ownership of the ENS is transferred to other people, the ownership of the domain name can be regained. The team immediately investigated the scope of the registry. Nearly 310,000 .ETH domain names were all updated, and there were also about 50,000 subdomains, .XYZ domain names, etc. The total cost of this migration was about $ 25,000.