Mynt and Zero

Please review how rewards are distributed based on the Immunefi Vulnerability Severity Classification System V2.2. This is a simplified 5-level scale system with separate scales for Smart Contracts and Websites/Apps.

Rewards for critical smart contract bug reports will be further capped at 10% of direct funds at risk if the bug discovered is exploited. However, there is a minimum reward of USD 50 000.

In cases of repeatable attacks, only the first attack is considered unless the smart contract cannot be upgraded or paused. If the attack impacts a smart contract directly holding funds that cannot be upgraded or paused, the amount of funds at risk will be calculated with the first attack being at 100% of the funds that could be stolen and then a reduction of 25% from the amount of the first attack for every 300 blocks the attack needs for subsequent attacks from the first attack, rounded down. For avoidance of doubt, if a second attack would happen at 600 blocks and then a third at 900 blocks, the funds at risk would be counted at 50% and 25% from the first attack, respectively.

Payouts and Payout Requirements:

Payouts are handled by the Sovyrn team directly and are denominated in USD. However, payouts are done in RBTC and SOV. The payment is made up of 50% in RBTC and 50% in SOV in a 24 month vesting contract.

Sovyrn commits to honoring payouts according to the terms set out in this program at the time of report submission, and to treat this program as the agreement and source of truth concerning bug reports and responsible disclosures.

For the purposes of determining report validity, this is a Primacy of Impact program.

Learn more about report validity best practices here: Best Practice - Primacy of Impact vs Primacy of Rules.

KYC Requirements

Zero and Mynt does not have a Know Your Customer (KYC) requirement for bug bounty payouts.

Audit Discoveries and Known Issues

Bug reports covering previously-discovered bugs are not eligible for any reward through the bug bounty program. If a bug report covers a known issue, it may be rejected together with proof of the issue being known before escalation of the bug report via Immunefi.

Previous audits and known issues can be found at:

• https://github.com/DistributedCollective/sovryn-audits/blob/main/Smart%20Contract%20Audit_%20Zero.pdf
• https://github.com/trailofbits/publications/blob/master/reviews/LiquityProtocolandStabilityPoolFinalReport.pdf
• https://github.com/trailofbits/publications/blob/master/reviews/LiquityProxyContracts.pdf
• https://www.coinspect.com/liquity-audit/
• https://github.com/trailofbits/publications/blob/master/reviews/Liquity.pdf
• https://omniscia.io/sovryn-babelfish-protocol-v1/
• Issue with MocIntegration.sol when Fees are Introduced The function getDocFromDllrAndRedeemRBTC in MocIntegration.sol will always revert when fees are introduced for calling redeem (which is currently not the case) due to a require statement on line 86.

require( massetManager.redeemTo(address(doc), _dllrAmount, thisAddress) == _dllrAmount, "MocIntegration:: redeemed incorrect DoC amount" );

Once fees are introduced redeemTo would always return less than _dllrAmount.

• Missing Bridge Check in tokensReceived The function tokensReceived in MassetManager.sol lacks a check to ensure that it is called from the bridge. If an external entity relies on this event, it could result in an error, unexpected behaviour, or token loss.

• Two-Way Pointers Between Contracts Could Break Some contracts have two-way pointers that may break due to errors made by programmers or deployers. Ideally, modifying one contract should also modify the other. Examples of such contracts include MassetManager <-> DLLR, and MassetManager <-> BasketManagerV3.

• mint Can be Called on MetaAssetToken While transfer, transferFrom, and transferWithPermit have recipient checks in place, mint does not. As a result, it can be called with the MetaAssetToken contract as a recipient.

• Changing factor and bridge of a Basset Can Break Usage There is currently no check to ensure that there are no massets issued for a basset before changing its factor or bridge, which could potentially result in a bad ratio between masset and basset. I suggest a require statement be added to these functions.

• Malicious Bridge Can Cause Griefing A malicious or compromised bridge for a specific basset could force a user to convert their massets into that basset using redeemByBridge in MassetManager, even if the user has no interest in the basset or does not trust the bridge or token. I recommend that a signature check be added to this function.

• Lack of Owner Check in upgradeToV3 The call to upgradeToV3 is in a separate transaction from deployment or initialization, and could potentially be front-run. There is currently no owner check in place for this function.