Missing events for owner/governor only functions that change critical parameters

[code423n4]

Handle

defsec

Vulnerability details

Impact

Owner/governor only functions that change critical parameters should emit events. Events allow capturing the changed parameters so that off-chain tools/interfaces can register such changes with timelocks that allow users to evaluate them and consider if they would like to engage/exit based on how they perceive the changes as affecting the trustworthiness of the protocol or profitability of the implemented financial services. The alternative of directly querying on-chain contract state for such changes is not considered practical for most users/usages.

Missing events and timelocks do not promote transparency and if such changes immediately affect users’ perception of fairness or trustworthiness, they could exit the protocol causing a reduction in liquidity which could negatively impact protocol TVL and reputation.

There are owner functions that do not emit any events in VaderBond.sol

Proof of Concept

Missing events

https://github.com/Badger-Finance/badger-ibbtc-utility-zaps/blob/6f700995129182fec81b772f97abab9977b46026/contracts/IbbtcVaultZap.sol#L116

https://github.com/Badger-Finance/badger-ibbtc-utility-zaps/blob/6f700995129182fec81b772f97abab9977b46026/contracts/IbbtcVaultZap.sol#L121

https://github.com/Badger-Finance/ibbtc/blob/d8b95e8d145eb196ba20033267a9ba43a17be02c/contracts/Zap.sol#L328

https://github.com/Badger-Finance/ibbtc/blob/d8b95e8d145eb196ba20033267a9ba43a17be02c/contracts/Zap.sol#L336

See similar High-severity H03 finding OpenZeppelin’s Audit of Audius (https://blog.openzeppelin.com/audius-contracts-audit/#high) and Medium-severity M01 finding OpenZeppelin’s Audit of UMA Phase 4 (https://blog.openzeppelin.com/uma-audit-phase-4/)

Tools Used

None

Recommended Mitigation Steps

Add events to all owner/governor functions that change critical parameters.

[0xleastwood]

duplicate of #55 which should be marked as non-critical