First Flight #10: One Shot
First Flight #10
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Submission Details
Severity: high
Invalid

Using ERC721.transferFrom() instead of safeTransferFrom() may cause the user's NFT to be frozen in a contract that does not support ERC721

tigerfrake

Summary

There are certain smart contracts that do not support ERC721.
In RapBattle.sol, the goOnStageOrBattle() allows the user to transfer their NFTs to the contract for a Rap Battle. Even so, the RapBattle.sol does not implement the IERC721Receiver to handle NFTs sent to it.

Using transferFrom() may result in the NFT being sent to such contracts.

Vulnerability Details

function goOnStageOrBattle(uint256 _tokenId, uint256 _credBet) external {
if (defender == address(0)) {
defender = msg.sender;
defenderBet = _credBet;
defenderTokenId = _tokenId;
​
emit OnStage(msg.sender, _tokenId, _credBet);
​
@> oneShotNft.transferFrom(msg.sender, address(this), _tokenId);
credToken.transferFrom(msg.sender, address(this), _credBet);
} else {
// credToken.transferFrom(msg.sender, address(this), _credBet);
_battle(_tokenId, _credBet);
}
}

As per the documentation of EIP-721:

A wallet/broker/auction application MUST implement the wallet interface if it will accept safe transfers.

Ref: https://eips.ethereum.org/EIPS/eip-721

Impact

The NFT may get stuck in the contract that does support ERC721.

Tools Used

Manual Review

Recommendations

Consider using safeTransferFrom() instead of transferFrom().

Updates

Lead Judging Commences

inallhonesty Lead Judge over 1 year ago
Submission Judgement Published
Invalidated
Reason: Incorrect statement

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