Ankr Bridge Exploited for $304.5K via Five Forged Receipts with Valid Signatures

Cointime reports: Ankr’s cross-chain bridge lost approximately $304,500 in an attack on November 9. The attacker referenced a single legitimate Optimism transaction to submit five forged cross-chain receipts — altering the recipient, token and withdrawal amount — all of which carried valid signatures from trusted bridge consensus signers. The withdrawal function released assets without independently verifying the actual source-chain event. SlowMist said the source of the unauthorized signatures is still under investigation and it has not confirmed that a signer was compromised.