Bug in Ethereum client leads to split — EVM-compatible chains at risk

A major consensus bug has affected more than half the Ethereum network’s nodes, causing those running older versions of Geth to split from the main network.

According to Ethereum software developer Marius van der Wijden, an unknown individual or group exploited a vulnerability affecting earlier versions of Geth, one of Ethereum's software clients. According to the developer, Geth clients and Ethereum nodes running software v1.10.7 or earlier are at risk of splitting from the network.

“Users that run validators need to update their nodes quickly (in the next 10h I think) as they would otherwise vote on invalid committees," said van der Wijden.

A chain split has occurred on the Ethereum mainnet. The issue was resolved in the v1.10.8 release announced previously. Please update your nodes, if you haven't already!

Binance Smart Chain’s Twitter account and others had previously warned Geth clients to update to v1.10.8, which claimed to have a hotfix for the vulnerability in the earlier versions. Ethereum Virtual Machine- or EVM-compatible chains may also be at risk. According to data from Ethernodes.org, 74.6% of all Ethereum nodes are running Geth, with only 28.4% of Geth clients currently running v1.10.8, meaning roughly 53% of all nodes on the network are potentially at risk. 

“Stay away from doing [transactions] for a while till confirmed, unless you are sure you are submitting to latest Geth,” advised Yearn.finance founder Andre Cronje

Related: Ethereum London hard fork goes live

Though software bugs have previously threatened nodes on the Ethereum network, this incident seems to be one of the biggest affecting a major blockchain. In August 2020, roughly 12% of the network’s nodes were unusable after a bug compromised half of the Parity nodes and all OpenEthereum nodes.

At the time of publication, the price of Ether (ETH) seems to be unaffected by the split. Data from Cointelegraph Markets Pro shows the ETH price is $3,241, having risen more than 4% in the last 24 hours.