Submission Details
Severity:
`tokenURI` function doesn't check if an ID exists
Description
The tokenURI function allows any user to retrieve the URI to access metadata for any NFT. However, if an ID does not exist, the function will return the URI for a Common Snek instead of reverting.
def tokenURI(token_id: uint256) -> String[53]:
rarity: uint256 = self.tokenIdToRarity[token_id]
return self.rarityToTokenURI[rarity]
Risk
Likelyhood: Low
Occurs each time the function is called with a non-existing ID
Impact: Low
Returns the URI for a Common Snek, which may lead to unexpected behavior or confusion for users interacting with the contract
Proof of Concept
PoC to add in `snek_raffle_test.py`
def test_uninitialized_rarity(
raffle_boa
):
# URI for common snek
assert raffle_boa.tokenURI(10000) == "ipfs://QmSQcYNrMGo5ZuGm1PqYtktvg1tWKGR7PJ9hQosKqMz2nD"
Recommended Mitigation
Ensure that the token exists before retrieving its URI.
def tokenURI(token_id: uint256) -> String[53]:
+ assert ERC721._exists(token_id)
rarity: uint256 = self.tokenIdToRarity[token_id]
return self.rarityToTokenURI[rarity]
Rewards breakdown
nSLOC
136This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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