Summary
VaultV2::accrueInterestView() rounds down when applying the perfomance and management fees, leading to reduce interest payments for the protocol.
Vulnerability Detail
Since the Vault uses a decimal offset to always have 18 decimals, the difference should be negligible, but it is something to keep in mind, especially as gas prices keep decreasing and $WBTC price keeps increasing. For this reason protocols often round up when calculating fees, though it may not be necessary in this case.
Impact
Wei interest loss.
Code Snippet
Tool Used
Manual Review
Recommendation
Consider rounding up, though the impact is negligible here.