Beedle - Oracle free perpetual lending

Summary

Hardcoding Pool Fees restrict Fees.sol to only uses Uniswap Pools with the hardcoded fees, which can be a problem if there is no pool available for the token pair.

Vulnerability Details

Since Fees.sellProfits() allows for any token address to be inputted by the user, it can be a token which doesn't have a Uniswap Pool with 0.3% fees.
Therefore the user calling sellProfits() won't be able to swap his tokens for WETH and his tokens will be stuck in the Fees.sol contract.
Or it can lead the user to lose value on his swap because he is forced to use a 0.3% fees pool when a 0.05% or 0.01% pool is available.

Impact

User funds stuck or unfavorable swap using wrong pool.

Tools Used

Manual Review

Recommendations

Don't hardcode the fees as recommended by Uniswap docs: "In production, you would likely use an input parameter for this, allowing you to change the pools and tokens you are interacting with on a per transaction basis."