Briefing
The Garden Finance protocol was compromised via a systemic attack on a single, privileged off-chain “solver,” resulting in an estimated $11 million in stolen assets. This incident immediately exposed the critical security gap between on-chain smart contract integrity and the centralized trust required by external operational infrastructure. The attacker successfully drained the solver’s inventory across multiple connected chains, demonstrating how a single point of failure in a hybrid architecture can lead to a multi-chain financial contagion. The total quantified loss is estimated at $11 million, with the core protocol smart contracts remaining technically uncompromised.
Context
The prevailing security posture in hybrid DeFi protocols often prioritizes smart contract immutability while under-auditing the operational security of off-chain components like solvers or relayers. This creates a known attack surface where the economic security of on-chain assets is still fundamentally reliant on the private key management and access controls of external systems. The risk of a centralized key compromise, which grants administrative privileges over decentralized assets, was a clear and present danger before this exploit.
Analysis
The attacker did not exploit a flaw in the core smart contract logic but rather targeted the access control mechanism of a single “solver” responsible for executing peer-to-peer transactions. By compromising the solver’s privileged key or its operational environment, the threat actor gained the authority to initiate unauthorized transactions from the solver’s inventory. This allowed the attacker to systematically drain the multi-chain assets held within that specific component’s custody. The success of the attack was predicated on the solver’s elevated permissions, which were necessary for its intended function but created a single, high-value target for exploitation.
Parameters
- Total Funds Drained ∞ $11,000,000 (Estimated loss from the compromised solver inventory)
- Attack Vector ∞ Compromised Off-Chain Solver (Exploitation of a privileged external component’s access control)
- Affected System ∞ Solver Inventory (Assets held by the external execution component, not the core protocol contracts)
- Incident Date ∞ October 30, 2025 (The date the breach was disclosed)
Outlook
Protocols must immediately conduct a zero-trust review of all external infrastructure and privileged accounts, treating off-chain components with the same rigor as core smart contracts. The contagion risk is high for any hybrid DeFi system that relies on a centralized “admin” or “solver” key to manage multi-chain liquidity. This incident will likely accelerate the adoption of new security standards, mandating multi-party computation (MPC) or time-locked governance for all privileged operational keys to minimize the blast radius of a single key compromise.
Verdict
The Garden Finance breach serves as a decisive strategic warning that the weakest link in decentralized finance is now the centralized, privileged access point of its external operational infrastructure.
