Bug Hunter Analysis of NFT Protocols
What are NFTs?
Non-Fungible Tokens (NFTs) are unique digital tokens recorded on-chain that act as tamper-proof certificates of ownership for a specific item— typically artwork, media files, game assets, or membership passes.
Unlike fungible cryptocurrencies, every NFT carries a one-of-a-kind ID tied to its contract address, so it cannot be swapped 1-for-1 with another token.
This baked-in uniqueness allows:
- verifiable ownership & provenance,
- programmable features such as royalties or gated access, and
- instant portability across wallets, marketplaces, and apps.
As NFT platforms execute hundreds of thousands of on-chain actions per day, smart-contract reliability is critical. Manual reviews are slow and error-prone, and legacy static-analysis tools generate too many false positives.
Bug Hunter is an automated Solidity code reviewer that delivers precise, low-noise insights early in development, with < 5 % false-positive rate. The following sections explore its performance on a range of NFT protocols and the key vulnerabilities it detects.
Analyzing NFT Protocols with Bug Hunter
We assessed Bug Hunter on five NFT projects (Table 1) by comparing its findings against the ground-truth issues reported by professional auditors.
Table 1 — Bug Hunter vs. Human Audits (all findings)
| Project | Audit Findings (total H/M/L) | Bug Hunter Findings (total H/M/L) | Accuracy |
|---|---|---|---|
| Traitforge | 37 (6 / 19 / 12) | 18 (4 / 9 / 5) | 48 % |
| Infinity | 27 (11 / 9 / 7) | 15 (6 / 6 / 3) | 55 % |
| OpenSea Seaport | 27 (2 / 2 / 23) | 13 (1 / 1 / 11) | 48 % |
| NFTX | 22 (4 / 8 / 10) | 11 (2 / 5 / 4) | 50 % |
| Unlock | 50 (4 / 14 / 32) | 26 (2 / 8 / 16) | 52 % |
| Aggregate | 163 (27 / 52 / 84) | 83 (15 / 29 / 39) | 50 % |
With an overall 50 % accuracy, Bug Hunter surfaced roughly half of all auditor-confirmed issues—an excellent first pass that slashes review time.
Common Core Functions in NFT Protocols
Most NFT projects share a familiar set of ERC-721 / ERC-1155 primitives plus marketplace helpers and admin utilities.
Click to view the full list …
Token-Contract Basics
_safeMint(), _mint(), mintBatch(), transferFrom(), safeTransferFrom(), approve(), setApprovalForAll(), _burn(), ownerOf(), balanceOf(), tokenURI(), totalSupply(), royaltyInfo(), setUser(), pause(), unpause()
Marketplace & Trading
listItem(), cancelListing(), buyItem(), placeBid(), acceptBid(), withdrawProceeds(), internal payout helpers
Admin & Maintenance
setBaseURI(), reveal(), grantRole(), transferOwnership(), initialize(), upgradeTo(), sweep()
Table 2 — Bug Hunter on Common Core Functions
| Project | Core-Function Findings (audit) | Core-Function Findings (Bug Hunter) | Accuracy |
|---|---|---|---|
| Traitforge | 16 (1 / 6 / 9) | 10 (1 / 5 / 4) | 62.5 % |
| Infinity | 20 (8 / 6 / 6) | 14 (6 / 6 / 2) | 70 % |
| OpenSea Seaport | 9 (1 / 1 / 7) | 8 (1 / 1 / 6) | 88 % |
| NFTX | 8 (1 / 1 / 6) | 4 (1 / 1 / 2) | 50 % |
| Unlock | 17 (1 / 3 / 13) | 9 (1 / 2 / 6) | 52 % |
| Aggregate | 70 (12 / 17 / 41) | 45 (10 / 15 / 20) | 64 % |
Bug Hunter catches nearly two-thirds of issues in this battle-tested code, giving teams early confidence while they iterate.
Protocol-Specific Functions & Unique Features
Each protocol introduces bespoke modules where the most interesting (and riskiest) logic lives.
Traitforge — Competitive Breeding + Nuke-Fund Game
- Dynamic-price minting & generations:
mintWithBudget,mintToken,_incrementGeneration - Forge mechanic:
listForForging→forgeWithListedwithforgePotentialchecks - Nuke-Fund burn-to-earn:
nuke()triggers ETH payout based oncalculateNukeFactor
Infinity — Order-Book NFT Marketplace
- Complication contracts (
canExecMatchOrder,doItemsIntersect) encode matching logic - Gas-refund pipeline in
matchOneToOneOrders,matchOneToManyOrders - Governance knobs (
updateWethTransferGas,updatePenalties,updateProtocolFeeBps)
OpenSea Seaport — Composable Marketplace & Advanced Orders
fulfillAdvancedOrder, Yul helpers in_applyCriteriaResolvers- Criteria-based matching via Merkle proofs
- Conduits for batched token transfers
NFTX — Vault-Based NFT Index & Liquidity
- Flash-mint via ERC-3156
flashLoan - Fee distribution & staking (
NFTXFeeDistributor.distribute,NFTXLPStaking) - Random vs. specific redeem (
getRandomTokenIdFromFund)
Unlock Protocol — Time-Locked Membership NFTs + UDT Emissions
- Key lifecycle (
purchase,shareKey,cancelAndRefund) - UDT reward engine in
recordKeyPurchase - Upgradeable lock templates (
upgradeLock, owner-controlledProxyAdmin)
Table 3 — Bug Hunter on Protocol-Specific Logic
| Project | Protocol-Specific Findings (audit) | Protocol-Specific Findings (Bug Hunter) | Accuracy |
|---|---|---|---|
| Traitforge | 21 (5 / 13 / 3) | 8 (3 / 4 / 1) | 38 % |
| Infinity | 7 (3 / 3 / 1) | 1 (0 / 0 / 1) | 14 % |
| OpenSea Seaport | 18 (1 / 1 / 16) | 5 (0 / 0 / 5) | 33 % |
| NFTX | 14 (3 / 7 / 4) | 7 (1 / 4 / 2) | 50 % |
| Unlock | 33 (3 / 11 / 19) | 17 (1 / 6 / 10) | 51 % |
| Aggregate | 93 (15 / 35 / 43) | 38 (5 / 14 / 19) | 40 % |
Bug Hunter’s hit rate drops on bespoke code—highlighting where human auditors add the most value.
Conclusive Remarks
Bug Hunter currently covers about half of all issues across full NFT protocols and nearly two-thirds of bugs in the common, reusable components. That clears vast amounts of low-hanging risk early, letting auditors focus on the novel logic where human judgment matters most.
Placing Bug Hunter at the start of the security pipeline:
- Gives developers rapid feedback while iterating.
- Frees auditors to spend time on complex edge cases.
- Ultimately delivers sturdier contracts to builders, investors, and collectors.
Together, automated analysis and expert review form the strongest foundation for the next wave of NFT innovation.