Submission Details
Severity:
Token ID 0 is skipped due to pre-increment of `eggCounter`
Vulnerability Details
The eggCounter variable, which determines the tokenId for newly minted NFTs, is incremented before the eggNFT.mintEgg function is called within searchForEgg. Assuming eggCounter starts at 0, this logic ensures the first minted egg will have tokenId 1, the second tokenId 2, and so on, preventing tokenId 0 from ever being minted.
if (random < eggFindThreshold) {
eggCounter++; // Counter incremented here
//@audit-issue tokenId 0 will never be minted as eggCounter is incremented before minting
eggsFound[msg.sender] += 1;
// Mint function called with the already incremented value
eggNFT.mintEgg(msg.sender, eggCounter);
emit EggFound(msg.sender, eggCounter, eggsFound[msg.sender]);
}
Impact
The NFT with token ID 0 will never be minted.
Recommendation
Increment the eggCounter state variable after calling the eggNFT.mintEgg function to allow minting to begin from token ID 0.
Rewards breakdown
nSLOC
129This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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