Nexus Mutual

Nexus Mutual is a discretionary mutual offering a decentralized alternative to insurance.

Nexus Mutual is interested in securing its smart contracts and preventing economic attacks on the bonding curve, funds being stolen from the capital pool or users, funds being locked or rendered inaccessible to their owners, in addition to blocking users from performing other users’ actions on their behalf that would risk or put their funds in danger.

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.

Payouts are handled by Nexus Mutual directly and are estimated in USD. However, payouts are done in stablecoins.

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

Smart Contracts/Blockchain:

• Re-entrancy
• Logic errors
  • including user authentication errors
• Solidity/EVM details not considered
  • including integer over-/under-flow
  • 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 that rely on social engineering
• Attacks requiring access to leaked keys/credentials

Smart Contracts/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 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
• Disassembly or reverse engineering of binaries for which source code is not published, not including smart contract bytecode
• Public disclosure of an unpatched vulnerability in an embargoed bounty