Submission Details
Impact:
Likelihood:
Incorrect Balance Accounting for Deflationary / Fee-On-Transfer Tokens
Root + Impact
Description
`createSellOrder` records `_amountToSell` without verifying how many tokens the contract actually received.
IERC20(_tokenToSell).safeTransferFrom(msg.sender, address(this), _amountToSell);
// balance delta not checkedhttps://commonmark.org/help/
orders[orderId].amountToSell = _amountToSell;
Risk
Impact:
If `_tokenToSell` charges transfer fees or is deflationary, the contract’s balance will be smaller than `amountToSell`. Any later `buyOrder` attempting to transfer that recorded amount will revert forever, locking seller funds.
Proof of Concept
Recommended Mitigation
Record `actualAmountReceived = balanceAfter – balanceBefore` and store that instead, or explicitly forbid deflationary / fee-on-transfer tokens.
Updates
Rewards breakdown
nSLOC
217This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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