🚨 Ethereum Classic Chain Split Announcement — Sept 03 2021

[ Update: The ETC network recovered in 48 hrs since the Geth exploit was deployed. Users should ensure their service is updated and service providers should ensure their services are updated and functioning on mainnet.]

Dear Ethereum Classic stakeholders,

The Geth exploit that split the Ethereum mainnet has now split the Ethereum Classic mainnet. Firstly,

  1. If you are a Core-geth node operator, then you must update your node to version 1.12.1 or later which contains the critical security patch.
  2. If you are a Hyperledger Besu node operator, then there’s no need to update since the vulnerability is specific to Go-Ethereum distributions.

From initial observation, ~20% of the ETC mainnet hash rate had fallen off. These are likely miners/ pools using the unpatched version of Core-geth. Thankfully major miners/ pools have already updated to the patched release of Core-geth or using Hyperledger Besu.

Blockscout, Ethercluster, and Expedition ETC mainnet services are intact. So, if you’re an ETC service provider using these public utilities, you can be assured they’re on the correct chain. If you’re an ETC service provider using your own node infrastructure, then ensure you’re on the correct chain and using Besu or at-least Core-geth v1.12.1 to provide the Ethereum Classic mainnet.

You can see a list of mining pools some of whom are producing invalid blocks here. These are likely the miners/ pools that need to come back to mainnet.

The fork monitor used for the recent Magneto hard-fork shows the status of the incorrect chain. Notice Core-geth v1.12.0 is the un-patched node.

DISCLAIMER This is an emergent and evolving highly technical space. If you choose to implement the recommendations in this post and continue to participate, you should make sure you understand how it impacts you. You should understand that there are risks involved including but not limited to risks like unexpected bugs. By choosing to implement these recommendations, you alone assume the risks of the consequences. This post and recommendations are not a sale of any kind and do not create any warranties of any kind including but not limited to any relating to the Ethereum Classic network or the Ethereum Classic clients referred to herein.