Submitted by jayphbee, also found by V_B, Decurity, gz627, joestakey, 0xc0ffEE, corerouter, SinceJuly, carlitox477, rbserver, Vadis, 0x52, chaduke, and aviggiano
https://github.com/code-423n4/2022-11-looksrare/blob/main/contracts/lowLevelCallers/LowLevelETH.sol#L35
https://github.com/code-423n4/2022-11-looksrare/blob/main/contracts/lowLevelCallers/LowLevelETH.sol#L46
https://github.com/code-423n4/2022-11-looksrare/blob/main/contracts/lowLevelCallers/LowLevelETH.sol#L57
The call opcodes return value not checked, which could lead to the originator losing funds.
The caller of LooksRareAggregator.sol::execute could be a contract who may not implement the fallback or receive function, when a call to it with value sent, it will revert, thus failed to receive the ETH.
Lets imagine the contract calls the execute function to buy multiple NFTs with ETH as the payout currency and make the isAtomic parameter being false. Since the batch buy of NFTs is not atomic, the failed transactions in LooksRare or Seaport marketplace will return the passed ETH. The contract doesnt implement the fallback/receive function and the call opcodes return value not checked, thus the ETH value will be trapped in the LooksRareAggregator contract until the next user call the execute function and the trapped ETH is returned to him. The originator lose funds.
Check the return value on the call opcode.
0xhiroshi (LooksRare) confirmed
Picodes (judge) decreased severity to Medium and commented:
