Lien Finance suffered a loss of approximately $542,000 due to an attack where the attacker exploited a vulnerability to steal USDC

According to Slow Fog monitoring, the decentralized finance protocol Lien Finance was attacked. The attacker exploited a smart contract vulnerability to mint uncollateralized bond tokens and stole approximately $542,000 USDC.

Using this vulnerability, the attacker successfully minted new non-anomalous BondTokens without destroying the corresponding input bonds and exchanged USDC through a pre-authorized address, ultimately transferring about 542,144.63 USDC from the victim's address. Analysis indicates that this incident was essentially due to a validation flaw in the bond token exchange logic, allowing the attacker to bypass asset collateral constraints and mint unsupported assets.