Pieces Protocol
First Flight #32
Beginner FriendlyFoundrySolidityNFT
100 EXP
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Submission Details
Severity: high
Valid

NFTs with the same address, but different tokenId can't be claimed

0xdimo

Summary

The protocol exposes functionality to split an NFT to ERC20s, which we call pieces. Each NFT can later be claimed back if a user decides to collect all the pieces and exchange them back for the NFT.

The vulnerable part is that the claimNft function will only take nftAddress as a parameter. This means that the user can't specify the tokenId, which he'd like to claim. Considering that the nftToErc20Info storage variable is never cleared of the claimed NFTs, this would cause previously divided NFTs with the same address, but different tokenIds to be forever stuck in the protocol.

PoC

function testDuplicateNFTAddress() public {
//NFT 0 is divided by USER
vm.startPrank(USER);
erc721Mock.approve(address(tokenDivider), TOKEN_ID);
tokenDivider.divideNft(address(erc721Mock), TOKEN_ID, AMOUNT);
ERC20Mock erc20Mock = ERC20Mock(tokenDivider.getErc20InfoFromNft(address(erc721Mock)).erc20Address);
console.log("ERC20 Token addres is: ", address(erc20Mock));
vm.stopPrank();
​
//NFT 1 is divided by USER2
vm.startPrank(USER2);
erc721Mock.approve(address(tokenDivider), 1);
tokenDivider.divideNft(address(erc721Mock), 1, AMOUNT);
ERC20Mock erc20Mock2 = ERC20Mock(tokenDivider.getErc20InfoFromNft(address(erc721Mock)).erc20Address);
console.log("ERC20 Token addres is: ", address(erc20Mock2));
vm.stopPrank();
​
vm.startPrank(USER);
vm.expectRevert(TokenDivider.TokenDivider__NotEnoughErc20Balance.selector);
//fails as USER does not have enough ERC20s for NFT 1
tokenDivider.claimNft(address(erc721Mock));
vm.stopPrank();
}

Impact

NFTs with the same address, but different tokenIds will be forever stuck in the protocol.

Tools Used

Manual Review

Recommendations

Add the parameter of tokenId to claimNft function.

Updates

Lead Judging Commences

fishy Lead Judge 5 months ago
Submission Judgement Published
Validated
Assigned finding tags:

Wrong nft collection handling

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