Arbitrum

Arbitrum is a scaling solution for Ethereum developed by Offchain Labs that drastically reduces costs and latency. An "Optimistic Rollup", Arbitrum instantly scales apps, reducing costs and increasing capacity, without sacrificing Ethereum's security. Arbitrum validators optimistically post updates to Ethereum, and the protocol uses an interactive fraud proof mechanism to resolve any disputes efficiently with a minimal on-chain footprint. Porting contracts to Arbitrum requires no code changes or downloads as Arbitrum is fully compatible with most existing Ethereum developer tooling. Arbitrum has just launched its mainnet beta, Arbitrum One, on Ethereum mainnet.

For more information about Arbitrum, please visit https://github.com/OffchainLabs/arbitrum.

This bug bounty program is focused on their smart contracts and is focused on preventing the following impacts:

• Loss of user funds by permanent freezing or direct theft
• Temporary freezing of funds
• Unable to call smart contract
• Network shutdown
• Smart contract gas drainage

Rewards are distributed according to the impact of the vulnerability based on the Immunefi Vulnerability Severity Classification System. This is a simplified 5-level scale, with separate scales for websites/apps and smart contracts/blockchains, encompassing everything from consequence of exploitation to privilege required to likelihood of a successful exploit.

All bug reports must come with a PoC in order to be considered for a reward.

Critical bug reports are capped at 10% of economic damage, primarily considering the funds at risk, and taking into account branding and PR issues, at the discretion of the team. However, rewards for Critical bug reports have a minimum reward of USD 50 000.

Payouts are handled by the Offchain Labs team directly and are denominated in USD. However, payouts are done in USDC.

All smart contracts of Arbitrum can be found at https://github.com/OffchainLabs/arbitrum and

https://github.com/OffchainLabs/arb-os/tree/develop/contracts/arbos/builtin.

However, only those in the Assets in Scope table are considered as in-scope of the bug bounty program.

Impacts in Scope

Only the following impacts are accepted within this bug bounty program. All other impacts are not considered as in-scope, even if they affect something in the assets in scope table.

Smart Contracts

• Loss of user funds by permanent freezing or direct theft
• Temporary freezing of funds other than withdrawals for one week or more
• Delaying withdrawals at no cost to the exploiter
• Unable to call smart contract
• Network shutdown
• Smart contract gas drainage

We are especially interested in receiving and rewarding vulnerabilities of the following types:

Smart Contracts and Blockchain

• Re-entrancy
• Logic errors
  • including user authentication errors
• Solidity/EVM details not considered
  • including integer over-/under-flow
  • including rounding errors
  • including unhandled exceptions
• Trusting trust/dependency vulnerabilities
  • including composability vulnerabilities
• Oracle failure/manipulation
• Novel governance attacks
• Economic/financial attacks
  • including flash loan attacks
• Congestion and scalability
  • including running out of gas
  • including block stuffing
  • including susceptibility to frontrunning
• Consensus failures
• Cryptography problems
  • Signature malleability
  • Susceptibility to replay attacks
  • Weak randomness
  • Weak encryption
• Susceptibility to block timestamp manipulation
• Missing access controls / unprotected internal or debugging interfaces

The following vulnerabilities are excluded from the rewards for this bug bounty program:

• Attacks that the reporter has already exploited themselves, leading to damage
• Attacks requiring access to leaked keys/credentials
• Attacks requiring access to privileged addresses (governance, strategist)

Smart Contracts and Blockchain

• Incorrect data supplied by third party oracles
• Not to exclude oracle manipulation/flash loan attacks
• Basic economic governance attacks (e.g. 51% attack)
• Lack of liquidity
• Best practice critiques
• Sybil attacks

The following activities are prohibited by this bug bounty program:

• Any testing with mainnet or public testnet contracts; all testing should be done on private testnets
• Any testing with pricing oracles or third party smart contracts
• Attempting phishing or other social engineering attacks against our employees and/or customers
• Any testing with third party systems and applications (e.g. browser extensions) as well as websites (e.g. SSO providers, advertising networks)
• Any denial of service attacks
• Automated testing of services that generates significant amounts of traffic
• Public disclosure of an unpatched vulnerability in an embargoed bounty