According to The Block, an anonymous white hat hacker "0xriptide" received a bug bounty reward of 400 ETH (about $520,000) for discovering a bridging vulnerability between Ethereum and Arbitrum Nitro. Caused $250 million in asset losses. According to "0xriptide", it began to look for vulnerabilities a few weeks before the Arbitrum Nitro upgrade, and finally found that the vulnerability allowed the bridge contract to complete initialization and accept deposits before it was launched, which means that hackers can set their own addresses as bridge addresses and imitate actual transactions. contract, and accept ETH deposits.