Tornado Cash Bug Bounty

Tornado Cash Bug Bounty

Hey everyone, thanks to this topic, we saw through a vote that the community is interested in a bug bounty program.

A snapshot will be set up asap by our dear @Rezan so that the community can vote. In the positive case, the bug bounty will be activated, in the negative case, the bug bounty will not be validated.

To be more specific, here is the list of what the bug bounty will cover:

  • Thefts or freezing of funds in anonymity pool
  • Thefts or freezing of unclaimed yield (TORN anonymity mining)
  • Theft of governance funds (Main on-chain Tornado DAO treasury only)
  • On chain governance activity disruption
    Beyond this list, no bounty will be granted.

The reward will depends on threat level. Immunefi classify vulnerability based on their own classification system.
Based on their 5-level classification system, here is what could be proposed:

  • Critical : 32,500 TORN (~ $1.3M)
  • High : 1625 TORN (~ $65k)
  • Medium : 525 TORN (~ $21k)

(The reward is set in TORN and not in dollars for simplicity, price in dollars are set based on actual TORN price - 40$/TORN).

Critical vulnerabilities have a cap of 10% of the economic damage. The minimum reward will be 2000 TORN in this case, with a maximum of 32,500 TORN, even in the case where 10% of the economic damage is more than 32,500 TORN.

The payment will be made by the Tornado Cash community multisig team and will be in TORN token.

Here are the smart contracts that will be part of this bug bounty program:
(You can find these smart contracts on the Tornado Cash github)

However, only the vulnerabilities listed in the table above are concerned by the bug bounty.

Here are the priority vulnerabilities:

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

Out of Scope & Rules

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)
  • Severe break of privacy due to issues with the SNARK logic/code
  • Lack of liquidity
  • Best practice critiques
  • Sybil attacks
  • Centralization risks

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

I would like to thanks the Immunefi team for their work.


Thrilled to see this bug bounty up for vote

Question for @TravinImmunefi - if this passes, can we do some collaborative promotion together?