ETHPoW Suffers 38% Price Drop After Gnosis Omni Bridge Exploit

ETHPoW Exploit and Price Impact

A recent exploit targeting the Gnosis Chain's Omni Bridge resulted in the theft of 200 ETHW tokens. This incident occurred via a replay attack on the Ethereum Proof-of-Work (PoW) blockchain. The attack caused the ETHW token price to drop by over 38% within 24 hours, trading around $5 at the time of reporting.

Mechanism of the Attack

Blockchain security firm BlockSec identified that attackers replayed transaction data (calldata) from the Proof-of-Stake (PoS) chain onto the PoW chain. The exploit was possible due to the Omni Bridge's failure to correctly verify the chainID of cross-chain messages, allowing the same transaction to be executed on both chains.

Transfer and Exchange Involvement

The attackers initially transferred 200 ETHW via the Omni Bridge and then replayed the transaction on the PoW chain to obtain an additional 200 ETHW. Security firm CertiK reported that the stolen funds were moved to the MEXC exchange, likely for sale, which contributed to the price decline.

Developer Response and Implications

The ETHPoW development team emphasized that the vulnerability lay in the bridge's contracts, not their blockchain. They attempted to contact Omni Bridge to address the risk but received no response. BlockSec warned that similar vulnerabilities might exist in other protocols, potentially endangering other tokens on the PoW chain.

This incident underscores the importance of robust security measures in cross-chain bridges and the need for prompt communication between protocols to mitigate risks.