Submission Details
Severity:
[L-1] The `MondrianWallet::tokenURI` function may return an empty string
Description
The MondrianWallet::tokenURI is designed to return one of four Mondrian art token URI's but it returns an empty string in some cases which is unexpected
Impact
The Owners may not be able to get their corresponding tokens URI when they call MondrianWallet::tokenURI function
Proof of Concept
In the MondrianWallet::tokenURI function the token URI is selected by the statement uint256 modNumber = tokenId % 10 but since there are only 4 possible Mondrian Arts so the token URI returns an empty string in 6 out of 10 cases
function tokenURI(uint256 tokenId) public view override returns (string memory) {
if (ownerOf(tokenId) == address(0)) {
revert MondrainWallet__InvalidTokenId();
}
@> uint256 modNumber = tokenId % 10;
if (modNumber == 0) {
return ART_ONE;
} else if (modNumber == 1) {
return ART_TWO;
} else if (modNumber == 2) {
return ART_THREE;
} else {
return ART_FOUR;
}
}
Recommended Mitigation
Make the following changes in MondrianWallet::tokenURIfunction
function tokenURI(uint256 tokenId) public view override returns (string memory) {
if (ownerOf(tokenId) == address(0)) {
revert MondrainWallet__InvalidTokenId();
}
- uint256 modNumber = tokenId % 10;
+ uint256 modNumber = tokenId % 4;
if (modNumber == 0) {
return ART_ONE;
} else if (modNumber == 1) {
return ART_TWO;
} else if (modNumber == 2) {
return ART_THREE;
} else {
return ART_FOUR;
}
}
Rewards breakdown
nSLOC
89This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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