Crypto exchange Coinbase suffered a $300,000 loss due to a misconfigured interaction with decentralized exchange protocol 0x's "swapper" contract, enabling MEV (Maximal Extractable Value) bots to drain one of its corporate wallets. The incident occurred on August 14, 2025, when Coinbase mistakenly granted token approvals to the permissionless swapper contract – designed solely for executing swaps, not holding allowances.
Security researcher "deeberiroz" from Venn Network first identified the exploit, noting that MEV bots instantly drained the wallet once approvals went live. Coinbase Chief Security Officer Philip Martin confirmed it as an isolated issue tied to a corporate DEX wallet change, stressing that no customer funds were compromised. The bots exploited the contract's accessibility to transfer approved tokens directly to their addresses before Coinbase could revoke access.
Following the breach, Coinbase immediately revoked allowances and moved remaining assets to a secure wallet. While financially immaterial for the exchange, the incident underscores vulnerabilities in automated trading environments and highlights critical security lessons: rigorous smart contract audits, careful approval management, and proactive blockchain monitoring.