Slow Fog: The core issue of the Usual protocol facing Arbitrage attacks stems from the usual Vault system.

[Slow Mist: The core problem of the Usual protocol encountering arbitrage attacks originates from the usual Vault system] According to the monitoring of Slow Mist, the Usual protocol has encountered a complex arbitrage attack. The analysis revealed that the attackers exploited the price difference between the protocol's internal mechanisms and the external market. The core issue arises from the usual Vault system, which allows for the exchange of USD0++ and USD0 tokens at a fixed 1:1 ratio. However, these same tokens trade at different prices on external decentralized exchanges. The attacker cleverly created a custom liquidity pool and manipulated the trading path, causing the Vault to release USD0 tokens without receiving the expected sUSDS collateral. Subsequently, the attacker sold the acquired USD0 tokens on the external market at a price higher than the internal exchange rate, thus obtaining arbitrage profits.