[FMR-02M] Unsafe Incentive Owner Adjustment

[vm06007]

FMR-02M: Unsafe Incentive Owner Adjustment

Type	Severity	Location
Input Sanitization		FeeManager.sol:L195-L213, L219-L235

Description:

The FeeManager::changeIncentiveUSDA and FeeManager::changeIncentiveUSDB functions do not perform any sanitization in relation to the _newOwner, permitting the incentiveOwnerA to set the incentiveOwnerB as the _newOwner and vice-versa.

Such an action can reduce the incentiveUSD of the _newOwner improperly. Additionally, the aforementioned functions permit the incentive owner to set themselves, resetting their incentiveUSD to 0 incorrectly.

Impact:

The incentiveUSD entries of the system can significantly misbehave if incentive owner transfers are presently performed using unusual arguments.

Example:

function changeIncentiveUSDA(
    address _newOwner
)
    external
{
    if (msg.sender != incentiveOwnerA) {
        revert NotAllowed();
    }

    incentiveUSD[_newOwner] = incentiveUSD[
        incentiveOwnerA
    ];

    delete incentiveUSD[
        incentiveOwnerA
    ];

    incentiveOwnerA = _newOwner;
}

Recommendation:

We advise the code to prevent setting the _newOwner to either the incentiveOwnerA or the incentiveOwnerB, preventing the misbehaviours described.

[vm06007]

Addressed in: #165