Incident Overview
On May 28, 2025, Cork Protocol suffered a severe smart contract exploit resulting in the theft of approximately 3,760 wstETH (~$12 million).
The attacker exploited a vulnerability in Cork Protocol’s wstETH:weETH market, taking advantage of faulty exchange rate logic in the smart contract. According to security auditor Dedaub, the exploit was executed by manipulating the exchange rate via fake token issuance, allowing the attacker to mint or withdraw more value than should have been possible. The attack was initiated from a wallet funded by a likely third-party service provider, and the exploited funds — approximately $12M in wstETH — were immediately swapped for ETH.
The malicious contract involved in the attack was deployed just prior to the exploit. Cork Protocol, which has backing from a16z and OrangeDAO, is actively investigating the incident and has paused all other markets to prevent further loss.
Incident Report
Protocol Information
What the Attacker Needed to Succeed
Understanding the prerequisites for this type of attack helps auditors identify protocols that are most at risk and helps developers build better defenses.
What Auditors Should Check
If you're auditing a protocol with similar architecture to Cork V1, these are the critical security checks that could have prevented this incident (May 2025).
- Verify all logic paths related to Access control bypass via hook / Other are guarded by proper access controls and input validation - see the Access Control Attacks attack class for patterns
- Review privileged functions (owner, admin, governance) for potential abuse vectors - centralization risks should be documented and bounded with timelocks or multi-sigs
Master these auditing techniques with hands-on labs and real exploit scenarios in the Smart Contract Hacking course.
Free TrialRelated Attack Classes
The technique used in this hack maps to these vulnerability classes in our security curriculum:
Sources & References
Learn to Prevent the Next Cork V1
The Cork V1 hack is one of many attacks that skilled auditors are trained to detect before deployment. Master real exploit patterns and defense techniques with hands-on Web3 security training.