A Arbitrum smart contract audit is a security review of code deployed to Arbitrum, carried out against the Nitro (WASM-based EVM) execution model and written in Solidity / Stylus (Rust) — covering both the bug classes shared across Arbitrum Nitro rollup systems and the failure modes specific to Arbitrum.
Arbitrum Nitro is close enough to the EVM that contracts port cleanly and just different enough to break assumptions quietly: block.number tracks L1, gas behaves differently, and cross-chain calls arrive through retryable tickets that can expire.
The Arbitrum-specific findings we see most often are not exotic. They are time-based logic using block.number and getting L1 block numbers, gas stipends that no longer cover what they used to, and retryable tickets whose redemption failure leaves user funds stranded with no recovery path.
We review the Nitro-specific surface — retryable ticket lifecycle, sender aliasing, ArbGas and L1 data pricing, precompile behaviour, delayed inbox and force inclusion — on top of a full EVM review, and simulate against a Nitro fork.
Arbitrum runs on Nitro (WASM-based EVM), so it inherits the bug classes below from every system in that family.
Arbitrum contracts are written in Solidity / Stylus (Rust). See our Solidity audit methodology.
We fix a commit hash, agree the in-scope contracts and read your architecture docs, then build a threat model: who the actors are, what the trust boundaries are, and which invariants must never break. Nothing is reviewed against assumptions we have not written down.
Line-by-line review by at least two auditors working independently, focused on authorisation, accounting, upgrade paths, external integrations and the gap between what the code does and what the documentation claims it does. Most critical findings come from this phase, not from tooling.
Static analysers appropriate to the language, plus property-based fuzzing and invariant testing to push the system into states no unit test covers. Tooling is used to widen coverage, never to replace the manual pass.
Candidate findings are proven on a forked network with a working proof of concept. We report what an attacker can actually do and what it costs them, not a theoretical severity label.
Every finding gets a severity rating, reproduction steps, the affected code, the impact in concrete terms and a specific remediation. You get a draft for discussion before anything is finalised.
We re-test every remediation against the original proof of concept and check that the fix has not opened a new path. The final report is yours to publish.
Retryable ticket handling, L1 address aliasing, block.number and timestamp semantics, ArbGas and L1 data pricing, Arbitrum precompiles, and sequencer and force-inclusion behaviour — none of which exist on mainnet.
Yes. Rust-based Stylus contracts get a Rust-focused review plus close attention to the Solidity interop boundary, which is where the interesting bugs are.
Yes — the chain configuration itself, including custom gas tokens, sequencer permissions and bridge setup, plus the contracts deployed on it.
A repository or contract address, a commit hash to freeze the scope, whatever architecture or spec documentation exists, and a point of contact who can answer design questions. If documentation is thin we will write our understanding of the system back to you and ask you to confirm it — that step alone catches design-level bugs.
A single token contract is 24–48 hours. A typical dApp or mid-sized protocol runs one to two weeks. Large DeFi systems, L2s, bridges and ZK circuits are scoped per project after we have seen the code. We will give you a fixed timeline with the quote, not an estimate that moves.
Yes. Fix review is part of the engagement, not an upsell. We re-run the original proof of concept against your patched code and confirm the fix has not introduced a new path.
Send the repository and a commit hash through the contact form, message @bugtester25 on Telegram, or book a 30-minute scoping call. 200+ protocols audited · $4B+ secured · 0 hacks post-audit. Prefer email? info@safeedges.in.