Submission Details
Severity:
No erc721receiver check in HUFF code
Summary
No erc721receiver check in HUFF code
Vulnerability Details
There's no check in huff code if the nft receiver is smart contract.So minting carry on as succesful
Attack contract
// SPDX-License-Identifier: MIT
import {ERC721Enumerable, ERC721} from '../lib/openzeppelin-contracts/contracts/token/ERC721/extensions/ERC721Enumerable.sol';
import {HorseStore} from "./HorseStore.sol";
import {IERC721Receiver} from '../lib/openzeppelin-contracts/contracts/token/ERC721/IERC721Receiver.sol';
contract Attacker /* is IERC721Receiver */{
HorseStore public horseStore;
uint256 public horseId;
uint256 public counter=1;
constructor(address _horseAddr) {
horseStore=HorseStore(_horseAddr);
}
function mintHorse(uint256 _value)external{
require(_value!=0,"Value shouldnt be zero!");
for(uint i=0;i<_value;i++){
horseStore.mintHorse();}
}
function feedHorse(uint256 _horseId)external{
horseStore.feedHorse(_horseId);
}
function isHappyHorse(uint256 _horseId) external view returns(bool){
return horseStore.isHappyHorse(_horseId);
}
/* function onERC721Received(
address ,
address ,
uint256 tokenId,
bytes calldata
) external returns (bytes4){
horseId=tokenId;
if(counter>5){
counter++;
}
return IERC721Receiver.onERC721Received.selector;
} */
}
test suit
function testCanContractMintEvenwithoutERC721receiverInterface()public{
//current attack contracts erc721 receiver disabled..
//minting success..
attacker.mintHorse(1);
}
Impact
NFT might stuck in smart contract.
Tools Used
foundry
Recommendations
Implement safeMint function or use huffmate erc721 contract.
Updates
Lead Judging Commences
inallhonesty over 1 year ago
Submission Judgement Published Assigned finding tags:
Components of ERC721 not properly (or at all) implemented in HUFF
Rewards breakdown
nSLOC
460This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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