What happened
Wise Lending's Pendle LP-token pool was exploited through rounding errors in its share accounting. The attacker used carefully sized deposits and withdrawals as stealth donations to inflate the value of lending shares and extract pool assets.
Technical root cause
Precision loss in a nearly empty pool enabled stealth donations that inflated share value. Dust withdrawals could then burn a whole collateral share without removing the corresponding underlying value or repaying the position's debt.
How it happened
- The attacker reduced the targeted pool to a tiny share supply.
- Repeated deposits and withdrawals exploited rounding in _calculateShares, leaving underlying value behind as donations and inflating share value.
- Helper positions borrowed assets and withdrew dust collateral amounts. Rounding burned their entire collateral shares while leaving the debt outstanding.
- The attacker redeemed separately held shares against the remaining pool value, leaving the lending system with bad debt.
Protocol details
Classification
Protocol Logic / Borrowing and Lending / Token & Share Accounting
Protocol Type
Lending
Affected asset / contract
WISE
Implementation language
Solidity
Protocol links
Website
@Wise_Lending
Evidence
- report @spreekaway incident report twitter.com
- report @CyversAlerts incident report twitter.com
- analysis Web Archive archive.is
- analysis DeFiLlama defillama.com
- analysis Wise Lending Exploit — Lending-Share Price Inflation via Rounding Asymmetry + Bad-Debt Donation crypto.training
- analysis Wise Lending Hack Analysis blog.solidityscan.com
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