On May 8, 2024, we generated proofs for withdrawals from various L2s to Ethereum Mainnet. During this process we ran into an error generating the withdrawal proofs for the Mode network. We proceeded to reach out to the Mode team to investigate this issue, and later came to the conclusion that our contracts were configured with the incorrect messenger contract address, rendering the funds stuck on the bridge.
The misconfigured messenger address can be seen in the initialize call shortly after contract creation, where it was initially set to 0xc0d3c0d3c0d3c0d3c0d3c0d3c0d3c0d3c0d30007.
On May 10, we believe we found the most minimal change necessary that will allow the withdrawal to successfully move through the remaining states and into the rest of the ether.fi protocol on Ethereum mainnet.
We consulted Nethermind on our proposed solution to recover the locked funds, which was then proposed to the Mode team as a solution. Read more in the consultation report attached here.
As part of the sensitive operations involved in recovering the funds, the proof submission was crucial to execute at exactly the right time. Since it is permission-less, it prevented us from revealing anything until the recovery was successfully executed.
On Aug 1, 2024, the Mode team approved to rescue the funds directly by withdrawing it from Mode’s Portal contract.
We learnt important lessons during this process and document the improvements we've made to our process. Read more about that in our future preventative measures.