hash - 1:1 price is assumed b/w stETH and WETH

[sherlock-admin3]

hash

Medium

1:1 price is assumed b/w stETH and WETH

Summary

1:1 price is assumed b/w stETH and WETH

Vulnerability Detail

The oracle used for WETH is the constantPriceOracle which returns 1e18 as the price. For vault with wstETH and WETH as underlying tokens and WETH as the base asset, the price used for wstETH is the wstETH to stETH exchange ratio

link

    function getAnswer() public view returns (int256) {
        return int256(IWSteth(wsteth).getStETHByWstETH(10 ** decimals));
    }


    function latestRoundData()
        public
        view
        override
        returns (uint80, int256, uint256, uint256, uint80)
    {
        return (0, getAnswer(), block.timestamp, block.timestamp, 0);
    }

This assumes a 1:1 price relation for weth and steth which need not be true as steth can deviate from the weth price. Hence the valuation of the assets will be incorrect allowing user's to possibly gain from the price difference

For eg: if deposit ratio is [100,0:wstETH,weth], withdraw ratio is [0,100:wstETH,weth] and the price of steth drops, user can gain by depositng wstETH and withdrawing weth

Impact

Incorrect valuation of assets which will be used during deposits and withdrawals to determine the assets to be given out

Code Snippet

Tool used

Manual Review

Recommendation

Use eth/steth oracle instead of assuming 1:1 price relation

Duplicate of #266