What happened
On May 2, 2021, an attacker exploited flawed liquidity-share accounting in Spartan Protocol's BNB Smart Chain liquidity pools. Using a PancakeSwap flash loan, the attacker manipulated pool balances, minted and burned LP tokens at an inflated redemption value, and drained more than $30 million in SPARTA, BNB, and related assets. The flash loan supplied temporary capital, but the root cause was a smart-contract liquidity-accounting error.
Spartan later patched the calculation and introduced a community compensation process; no full recovery of the attacker's proceeds was confirmed.
`calcLiquidityShare()` read manipulable current pool balances instead of cached accounting balances, allowing temporary balance inflation to inflate an LP redemption.
Case & protocol details
Attack Timeline
The pool used current token balances when calculating how much a burned LP position could redeem. An attacker temporarily inflated those balances with flash-loaned WBNB and carefully timed swaps and liquidity additions. The contract then treated the attacker's LP tokens as entitled to an outsized portion of the pool.
Repeating this cycle drained real liquidity, after which the flash loan was repaid in the same transaction.
Evidence & learning
Attack pattern
Compare incidents →Proof of concept
1 available- Code Spartan Logic Flaw
Sources and on-chain records
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