As reported by Cointelegraph, the BitBTC team has now fixed the bug after Twitter user @PlasmaPower0 disclosed a “fake minting” bug that existed in the cross-chain bridge between BitBTC and Optimism. It is reported that the vulnerability allows an attacker to fake tokens on one side of the bridge and exchange them for real tokens on the other side. Attackers have tried to extract 200 billion BitBTC tokens from Optimism through this vulnerability, but it is only a test.