Summary

_harvestAndReport function in strategies is not implemented correctly, which will lead to wrong accounting.

Details

Yearn docs state [here] (https://docs.yearn.fi/developers/v3/strategy_writing_guide#_harvestandreport) that ⇒ _totalAssets: A trusted and accurate account for the total amount of 'asset' the strategy currently holds including loose funds.

But the _harvestAndReport function, in its current implementation, does not follow this. Let’s look at the function in StrategyMainnet.sol contract:

The function above fails in the following:

• Actually claim claimable rewards

• Swap underlying (WETH) to the asset (ALETH)

• Include claimable amount in total assets calculation

• Convert all balances to a consistent denomination (underlying or asset)

Some insights: You see that there is a note that suggests the swapping between underlying to asset can be done here, or in tending. But it is done in neither: First, it’s not done here, second, _tend is never utilized.

Also, according to the Yearn tokenized strategies docs, underlyingBalance here is not related to the _totalAssets. It should only be denominated in the asset, not in the underlying in this protocol.

The same issue persists in other strategies: StrategyArb.sol and StrategyOp.sol

Impact

This function will not work correctly. The accounting will be wrong.

Recommendation

Follow the yearn docs here strictly and make sure _totalAssets returns the correct value.