Mitigation Audit | Flare | FAssets-logo

Mitigation Audit | Flare | FAssets

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Flare is the blockchain for data. It is a layer-1, EVM smart contract platform designed to expand the utility of blockchain by delivering data certainty for dApp builders.

FAssets is a trustless, over-collateralized bridge built on Flare that connects non smart contract networks to Flare/Songbird. It enables the creation of wrapped tokens (FAssets) for assets like BTC, DOGE and XRP.

At the core of FAssets v1.1 is a new architecture component called the Core Vault, designed to improve system liquidity, scalability, and capital efficiency.

Solidity

Evaluating

17d: 12h remaining
Primary Pool
$17,500
All Stars Pool
$5,000
Podium Pool
$2,500
Start Date
18 September 2025
End Date
25 September 2025
Rewards Token
USDC
Lines of Code
50
  • Triaged by Immunefi

  • Step-by-step PoC Required

This Audit Competition Is Under Evaluation

Thank You to All Participating Security Researchers!

The audit competition has now concluded and is currently in the evaluation phase. During this period, all submitted reports are being carefully reviewed by the Immunefi triage team and the project team.

Start Date
18 September 2025 10:00 UTC
End Date
25 September 2025 10:00 UTC

Rewards

Mitigation Audit | Flare | FAssets provides rewards in USDC on Ethereum, denominated in USD.

Rewards by Threat Level

Smart Contract
Critical
Portion of Reward Pool
High
Portion of Reward Pool
Medium
Portion of Reward Pool
Low
Portion of Reward Pool
All categories *
Insight
Portion of the Reward Pool

Rewards are distributed among SRs according to Immunefi’s Standardized Competition Reward Terms.

Rewards are denominated in USD and distributed in USDC on Ethereum.

Flat Rewards

Mitigation Audit Rewards: The reward pool is $25,000 USD if any bug is found.

If not a single bug is found (Insights do not count as bugs) the reward pool is $3,750 USD

Program Overview

Flare is the blockchain for data. It is a layer-1, EVM smart contract platform designed to expand the utility of blockchain by delivering data certainty for dApp builders.

FAssets is a trustless, over-collateralized bridge built on Flare that connects non smart contract networks to Flare/Songbird. It enables the creation of wrapped tokens (FAssets) for assets like BTC, DOGE and XRP. The original assets are deposited to the address of an agent and can later be redeemed.

At the core of FAssets v1.1 is a new architecture component called the Core Vault, designed to improve system liquidity, scalability, and capital efficiency. It serves as a liquidity hub where Agents can deposit native assets (e.g., XRP) and unlock their FLR or SGB collateral. The minted FAssets are secured by collateral, which is in the form of ERC20 tokens on Flare/Songbird chain and native tokens (FLR on Flare, SGB on Songbird). These tokens can participate in Flare's DeFi ecosystem.

The FAsset system maintains security by ensuring every minted Fasset is backed by more value than it represents, creating a safeguard against volatility and protecting users from potential losses. Two protocols, available on Flare and Songbird blockchains, enable the FAsset system to operate:

  • FTSO contracts which provide decentralised price feeds for multiple tokens.
  • Flare’s Flare data connector, which bridges payment data from any connected chain. Flare provides rewards in USDC, denominated in USD. For more details about the payment process, please view the Rewards by Threat Level section further below.

For more information about Flare, please visit https://flare.network

This is the Mitigation Audit following the Flare FAssets Mainnet Audit Competition and the project may fix bugs mid-competition.

Audits

Auditor
All Audits
Completed at
1 April 2025
Auditor
Immunefi
Completed at
25 August 2025

Known Issues

Category
Smart Contract
Description / Link
Triggering instructions might run out of gas: the size of the allowed destination addresses will be low (5-10).
Last Updated At
16 September 2025
Category
Smart Contract
Description / Link
Array of escrows always grows: the number of escrows created will be low (if it is more than one or two, we will increase the daily escrow amount). So the total number of escrows will not be huge, perhaps a few hundred.
Last Updated At
16 September 2025
Category
Smart Contract
Description / Link
Escrows finalized close to expiry time decouple the Core Vault internal accountancy: before escrows are released, the triggering bots will be shut down, and they will only be enabled after setEscrowsFinished is called. So there will be no instructions triggered between escrow finalization and the corresponding update on the core vault manager.
Last Updated At
16 September 2025
Category
Smart Contract
Description / Link
Users are unprotected against missing or malformed vault redemption payments: in that case, we assume the core vault has full trust, and its redemptions don't have a time limit. Also, core-vault redeemers are special entities.
Last Updated At
16 September 2025

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

Default 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.