Woofun AI reports that Lien Finance experienced a security breach resulting in the theft of approximately $542,000 in USDC. The attacker exploited a vulnerability in the protocol's smart contract to mint uncollateralized BondTokens without destroying the corresponding input bonds. By leveraging a pre-authorized address, the attacker exchanged these tokens for USDC, transferring 542,144.63 USDC from the victim's address. Analysis confirms the incident stemmed from a verification flaw in the bond token exchange logic, which allowed the bypass of asset collateral constraints.