Symbiosis Bitcoin Bridge Vulnerability Incident: Hackers Mint Approximately 46.1 Billion USD syBTC

The on-chain security platform Blockaid discovered a vulnerability in the Bitcoin bridge of the cross-chain protocol Symbiosis, where attackers minted approximately 2^62 syBTC to a newly created externally owned account, valued at about 46.1 billion dollars when calculated to 8 decimal places, and sold about 4.39 WBTC on Uniswap V4 on Ethereum, realizing a cash-out of approximately 336,000 dollars.

Symbiosis stated that the attack occurred around 4:28 AM on September 11, and the team has suspended the BTC routing, while other routings remain operational and unaffected. The team has recovered about 15 Bitcoins and deposited them into a multi-signature wallet controlled by the team, while offering a 20% white hat bounty on the funds to the attackers, with a deadline of September 13.

In recent weeks, Liquid Network, Nomic, and Symbiosis have all experienced security incidents involving the expansion of supply by minting tokens without real asset backing. As of September 13, Symbiosis has not publicly disclosed a technical review of BridgeV2, the final loss amount, or confirmation on whether the attackers accepted the bounty.