Balancer is a decentralized automated market maker (AMM) and liquidity protocol on Ethereum and other EVM-compatible networks. It is permissionless and non-custodial: anyone can trade tokens or provide liquidity through smart contracts, with no intermediary holding funds.
Balancer V3 is the current protocol. It is built around a single Vault that holds all pool assets and enforces the core accounting and safety checks, which keeps pool contracts small and makes custom pool types simpler to build and review. V3 adds a hooks framework for extending pool behavior, native ERC4626 boosted liquidity through internal buffers, and pool types including Weighted, Stable, StableSurge, Gyro (E-CLP and 2-CLP), AutoRange (ReClamm), and Liquidity Bootstrapping Pools. Trades and liquidity operations are routed through a set of Routers.
Balancer V2, the prior generation, remains in operation for residual liquidity (mainly weighted pools) and is also built around a Vault. This program covers the in-scope V3 and V2 smart contracts listed under Assets in Scope.
PoC Required
Rewards
Rewards by Threat Level
Mainnet assets:
Reward amount is 10% of the funds directly affected up to a maximum of:
$1,000,000Rewards are distributed according to the impact of the vulnerability based on the Immunefi Vulnerability Severity Classification System V2.2. This is a simplified 5-level scale, with separate scales for websites/apps, smart contracts, and blockchains/DLTs, focusing on the impact of the vulnerability reported.
All Critical/High severity bug reports must come with a PoC with an end-effect impacting an asset-in-scope in order to be considered for a reward. Explanations and statements are not accepted as PoC and code is required.
Critical smart contract vulnerabilities are further capped at 10% of economic damage, taking into account the funds at risk at the moment of the bug report submission. However, there is a minimum reward of USD 100 000. Additionally, the maximum reward is capped at USD 1 000 000, even if 10% of the damage in USD equivalent is greater than USD 1 000 000.
High severity smart contract vulnerabilities are also further capped at 10% of economic damage, taking into account the funds at risk at the moment of the bug report submission. However, there is a minimum reward of 25 000 USD. Additionally, the maximum reward is capped at USD 200 000, even if 10% of the damage is greater than USD 200 000.
Vulnerabilities involving non-standard ERC20 tokens are considered out of scope, as it would be trivial to insert an exploit into a token for the sake of applying to this bug bounty. A standard, Balancer-compatible ERC20 token is one that conforms to all EIP-20 interfaces and exhibits expected behavior in implementation; i.e., transfers move exactly N tokens from sender to recipient, and balances do not change by any means other than transfers. Notably, tokens with transfer fees, rebasing supplies, streaming mechanics or multiple entrypoints are not compatible with Balancer, but that list is not exhaustive.
Following the same line, vulnerabilities that require the user to interact with explicitly malicious routers, pools, hooks or rate providers are out of scope. This is because introducing such vulnerabilities in a permissionless protocol is both trivial and impossible to prevent.
Known issues such as those previously highlighted in the following audit report are considered out of scope (list is not exhaustive):
- https://github.com/balancer/balancer-v2-monorepo/tree/master/audits
- https://github.com/balancer/balancer-v3-monorepo/tree/master/audits
- https://github.com/balancer/reclamm/tree/main/audits
Payouts are handled by the Balancer team directly and are denominated in USD. However, payouts are done in ETH or USDC, at the discretion of the team.
Program Overview
Balancer is a decentralized automated market maker (AMM) and liquidity protocol on Ethereum and other EVM-compatible networks. It is permissionless and non-custodial: anyone can trade tokens or provide liquidity through smart contracts, with no intermediary holding funds.
Balancer V3 is the current protocol. It is built around a single Vault that holds all pool assets and enforces the core accounting and safety checks, which keeps pool contracts small and makes custom pool types simpler to build and review. V3 adds a hooks framework for extending pool behavior, native ERC4626 boosted liquidity through internal buffers, and pool types including Weighted, Stable, StableSurge, Gyro (E-CLP and 2-CLP), AutoRange (ReClamm), and Liquidity Bootstrapping Pools. Trades and liquidity operations are routed through a set of Routers.
Balancer V2, the prior generation, remains in operation for residual liquidity (mainly weighted pools) and is also built around a Vault. This program covers the in-scope V3 and V2 smart contracts listed under Assets in Scope.
For more information about Balancer, please visit https://balancer.fi/.
Audits
Known Issues
KYC not required
No KYC information is required for payout processing.
Proof of Concept
Proof of concept is always required for all severities.
Prohibited Activities
- Any testing on mainnet or public testnet deployed code; all testing should be done on local-forks of either public testnet or mainnet
- 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 that are executed against project assets
- Automated testing of services that generates significant amounts of traffic
- Public disclosure of an unpatched vulnerability in an embargoed bounty
- Any other actions prohibited by the Immunefi Rules
Feasibility Limitations
The project may be receiving reports that are valid (the bug and attack vector are real) and cite assets and impacts that are in scope, but there may be obstacles or barriers to executing the attack in the real world. In other words, there is a question about how feasible the attack really is. Conversely, there may also be mitigation measures that projects can take to prevent the impact of the bug, which are not feasible or would require unconventional action and hence, should not be used as reasons for downgrading a bug's severity.
Therefore, Immunefi has developed a set of feasibility limitation standards which by default states what security researchers, as well as projects, can or cannot cite when reviewing a bug report.