DittoETH

Summary

Oracle uses inverted Uniswap TWAP price which may be inappropriate and can lead to incorrect results

Vulnerability Details

It is common when dealing with token prices to use inversion as in function below LibOracle.sol

The above is appropriate as its spot price of token0/token1 can be inverted to get the spot price of token1/token0.

However the above is not the case when working with TWAP price of token0/token1 due to how TWAP is calculated. Yet in the protocol when Oracle defaults to Uniswap TWAP inversion is still used to get the price. See below

Impact

This may lead to incorrect or inappropriate price values, extremely deviated prices especially if the more volatile the price of token0/token1

See following report for similar finding => Incorrect Use Time-Weighted Average Prices

Tools Used

Manual Analysis

Recommendations

It is recommended not to invert the prices when using TWAP prices. It may be ideal to perform own accumulator based inversion, or use such other appropriate mechanisms to avoid direct inversion prices