Incident Overview
On August 14 at around 11 am UTC, the Ref Finance dev team deployed a hotfix to an issue surrounding the Ref Finance contracts. Prior to the fix, users that unstaked all of their tokens from the farm contract were unable to remove the deposited liquidity from the pool. This occurred due to the users’ NEAR account being unregistered from the LP token contract, a feature unique to NEAR tokens that generally aids the user experience.
While the hotfix solved that issue, it contained a new issue that did not debit users’ LP token balances when they removed liquidity. This allowed a small number of users to continuously remove tokens, receiving far more tokens than they should have.
In total, 507,000 NEAR and ~1 million REF tokens were withdrawn using this exploit. Over 400,000 of the NEAR were sent to Binance and Huobi.
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 Ref Finance, these are the critical security checks that could have prevented this incident (August 2021).
- Verify all logic paths related to Other are guarded by proper access controls and input validation
- 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 TrialFunds Recovery
Recovered
$3.2M
Net Loss
0
Security Audit History
- Audit Report 1 Report
Sources & References
Learn to Prevent the Next Ref Finance
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