Incident Overview
Platypus Finance, an Avalanche-based DEX, was exploited in a reentrancy attack causing a loss of 51,840 $USD.
Platypus Finance faced an exploit that caused a loss of approximately $51k. The exploit emerged due to an issue with the liquidity conversion calculation for LP-USDC, which resulted in an excessively large quantity calculation for USDC.e when swapping USDC for USDC.e. The call to asset.addLiability() in the _deposit function caused an increase in the asset.liability() parameter in withdrawFrom, allowing the hacker to withdraw more USDC.e than the amount of USDC previously deposited.
The funds remain in the attacker's address, amounting to $31,120 worth of assets in Avalanche and $20,450 worth of $DAI in Ethereum chain.
Attacker Address:
https://showtrace.io/address/0xc64afc46…79521a
Malicious Transaction Example:
https://showtrace.io/tx/0x5e785b87…bab388
Malicious Contract Address:
https://showtrace.io/address/0x16a3c9e4…8f1ed8
Incident Report
Protocol Information
Market Context at Time of Hack
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 Platypus Finance, these are the critical security checks that could have prevented this incident (July 2023).
- Verify all logic paths related to Reentrancy 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:
Sources & References
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