Ethereum Developers Address Technical Glitches During Pectra Upgrade
On March 5,Ethereum faced unexpected challenges during the Pectra upgrade on the Sepolia testnet. Developers had to implement a “private fix” due to an attacker exploiting a technical loophole.
Marius van der Wijden, an Ethereum developer, explained the issue in a post-incident report. The attacker repeatedly sent zero-token transfers to the deposit contract, causing errors. This was an “edge case” that developers had overlooked.
The problem began when the deposit contract emitted a transfer event instead of a deposit event.This led nodes to reject transactions and produce empty blocks. The bug was linked to EIP-6110, which required uniform processing of logs from the deposit contract.
Initially,developers thought a trusted validator had made a mistake. However, they traced the issue to a newly funded account from a public faucet. To stop the attack, they needed to filter transactions interacting with the deposit contract.
Concerned about the attacker monitoring their chats, developers rolled out a “private fix” to select DevOps nodes. Onc deployed, nodes resumed normal operations by 14:00 UTC.
Despite the disruptions, Ethereum maintained finalization. The issue was limited to Sepolia, as it’s deposit contract differs from the mainnet’s.Developers have decided to delay the Pectra upgrade for further testing.
The pectra fork aims to enhance ETH staking, improve layer 2 scalability, and expand network capacity. It introduces 11 Ethereum Enhancement Proposals (EIPs) and is the first major upgrade as dencun in March 2024.
