03.DEFI ATTACKS - Falsche Slippagekalkulation

function withdraw(address _recipient, address _asset, uint256 _amount
) external onlyVault nonReentrant {
    // ...

    // Calculate how much of the pool token we need to withdraw
    (uint256 contractPTokens, , uint256 totalPTokens) = _getTotalPTokens();

    uint256 poolCoinIndex = _getPoolCoinIndex(_asset);
    // Calculate the max amount of the asset we'd get if we withdrew all the
    // platform tokens
    ICurvePool curvePool = ICurvePool(platformAddress);
    uint256 maxAmount = curvePool.calc_withdraw_one_coin(
        totalPTokens,
        int128(poolCoinIndex)
    );

    // Calculate how many platform tokens we need to withdraw the asset amount
    uint256 withdrawPTokens = totalPTokens.mul(_amount).div(maxAmount);

    // Calculate a minimum withdrawal amount
    uint256 assetDecimals = Helpers.getDecimals(_asset);
    // 3crv is 1e18, subtract slippage percentage and scale to asset
    // decimals
    // @audit not using user-provided _amount, but calculating a non-sensical
    // value based on the LP tokens
    uint256 minWithdrawAmount = withdrawPTokens
        .mulTruncate(uint256(1e18).sub(maxSlippage))
        .scaleBy(int8(assetDecimals - 18));

    curvePool.remove_liquidity_one_coin(
        withdrawPTokens,
        int128(poolCoinIndex),
        minWithdrawAmount
    );

    // ...
}

curvePool.remove_liquidity_one_coin(
    withdrawPTokens,
    int128(poolCoinIndex),
    _amount
);