Incident Overview
On July 15, 2024, Minterest experienced a malicious entry resulting in the theft of approximately $1,460,000 worth of mETH and ETH.
In July 2024, Minterest fell victim to a hack where an attacker stole approximately $1.4 million in cryptocurrency from the protocol by exploiting a reentrancy vulnerability through a flashloan attack on the Mantle Network. The attacker initiated the attack by taking a flashloan and borrowing USDY tokens from Minterest's flashLoan function, which triggered their fallback function, allowing them to manipulate the market’s exchange rates. This manipulation resulted in a lower cash balance for the market.
When Minterest's contract called the attacker's fallback function, the attacker converted USDY tokens to mUSD and reentered the Minterest contract via the lendRUSDY function, exploiting the modified exchange rate to receive excess mTokens. The attacker then withdrew the underlying tokens, causing Minterest to burn some mTokens but retain the excess. Repeating this process multiple times, the attacker accumulated an estimated $1.7 million in mTokens in the mUSDY market, which they used to borrow WETH and mETH, ultimately draining $1.4 million from the protocol.
This exploit also led to the liquidation of many user positions within the mUSDY market.
Attacker
https://etherscan.io/address/0x618f768a…1911d1
Funding by Tornado:
https://etherscan.io/tx/0x99fa85d1…15eaee
Example of the Tornado deposit:
https://etherscan.io/tx/0xe14c67b2…4d2710
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 Minterest, these are the critical security checks that could have prevented this incident (July 2024).
- Verify all logic paths related to Reentrancy / Other are guarded by proper access controls and input validation - see the Reentrancy attack class for patterns
- Check that all state-changing functions follow the Checks-Effects-Interactions (CEI) pattern to prevent reentrancy and logic ordering bugs
- 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:
Proof-of-Concept Exploits
Sources & References
- 01
- 02
Learn to Prevent the Next Minterest
The Minterest 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.