xWin Finance Hack

Reported loss $270K
BNB Chain
Other

What happened

xWin Finance was exploited through invalid slippage control in its xWinFund swap logic. Flash-loaned BNB let the attacker repeatedly collect excess xWIN rewards and sell them for BNB.

Technical root cause

Invalid slippage control in xWinFund's _swapBNBToTokens() allowed a flash-loan-funded sequence to extract excess xWIN rewards.

How it happened

  1. The attacker borrowed BNB through a Fortube flash loan.
  2. They swapped and supplied liquidity through the PancakeSwap V1 BNB/xWIN pool, exploiting xWin's invalid slippage control to receive extra rewards.
  3. They unwound the liquidity position and repeated the cycle to accumulate xWIN.
  4. The reward tokens were sold through PancakeSwap V2, and the flash loan was repaid.

Protocol details

Classification Yield Aggregator / Input Validation
Protocol Type Indexes
Affected asset / contract XWIN
Implementation language Solidity
Protocol links Website @xwinfinance

Security review history

Evidence

Same attack technique

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