Vulnerability: Different spot prices used during the comparison
Severity: high

Description:
The spot prices used during the comparison are different, which might result in the trade proceeding even if the pool is manipulated, leading to a loss of assets.\\n```\\nFile: BalancerComposableAuraVault.sol\\n    function _checkPriceAndCalculateValue() internal view override returns (uint256) {\\n        (uint256[] memory balances, uint256[] memory spotPrices) = SPOT_PRICE.getComposableSpotPrices(\\n            BALANCER_POOL_ID,\\n            address(BALANCER_POOL_TOKEN),\\n            PRIMARY_INDEX()\\n        );\\n\\n        // Spot prices are returned in native decimals, convert them all to POOL_PRECISION\\n        // as required in the _calculateLPTokenValue method.\\n        (/* */, uint8[] memory decimals) = TOKENS();\\n        for (uint256 i; i < spotPrices.length; i++) {\\n            spotPrices[i] = spotPrices[i] * POOL_PRECISION() / 10 ** decimals[i];\\n        }\\n\\n        return _calculateLPTokenValue(balances, spotPrices);\\n    }\\n```\\n\\nLine 91 above calls the `SPOT_PRICE.getComposableSpotPrices` function to fetch the spot prices. Within the function, it relies on the `StableMath._calcSpotPrice` function to compute the spot price. Per the comments of this function, `spot price of token Y in token X` and `spot price Y/X` means that the Y (base) / X (quote). Thus, secondary (base) / primary (quote).\\n```\\nFile: StableMath.sol\\n    /**\\n     * @dev Calculates the spot price of token Y in token X.\\n     */\\n    function _calcSpotPrice(\\n        uint256 amplificationParameter,\\n        uint256 invariant, \\n        uint256 balanceX,\\n        uint256 balanceY\\n    ) internal pure returns (uint256) {\\n        /**************************************************************************************************************\\n        //                                                                                                           //\\n        //                             2.a.x.y + a.y^2 + b.y                                                         //\\n        // spot price Y/X = - dx/dy = -----------------------                                                        //\\n        //                             2.a.x.y + a.x^2 + b.x                                                         //\\n        //                                                                                                           //\\n        // n = 2                                                                                                     //\\n        // a = amp param * n                                                                                         //\\n        // b = D + a.(S - D)                                                                                         //\\n        // D = invariant                                                                                             //\\n        // S = sum of balances but x,y = 0 since x  and y are the only tokens                                        //\\n        **************************************************************************************************************/\\n\\n        unchecked {\\n            uint256 a = (amplificationParameter * 2) / _AMP_PRECISION;\\n```\\n\\nThe above spot price will be used within the `_calculateLPTokenValue` function to compare with the oracle price to detect any potential pool manipulation. However, the oracle price returned is in primary (base) / secondary (quote) format. As such, the comparison between the spot price (secondary-base/primary-quote) and oracle price (primary-base/secondary-quote) will be incorrect.\\n```\\nFile: SingleSidedLPVaultBase.sol\\n    function _calculateLPTokenValue(\\n..SNIP..\\n                uint256 price = _getOraclePairPrice(primaryToken, address(tokens[i]));\\n\\n                // Check that the spot price and the oracle price are near each other. If this is\\n                // not true then we assume that the LP pool is being manipulated.\\n                uint256 lowerLimit = price * (Constants.VAULT_PERCENT_BASIS - limit) / Constants.VAULT_PERCENT_BASIS;\\n                uint256 upperLimit = price * (Constants.VAULT_PERCENT_BASIS + limit) / Constants.VAULT_PERCENT_BASIS;\\n                if (spotPrices[i] < lowerLimit || upperLimit < spotPrices[i]) {\\n                    revert Errors.InvalidPrice(price, spotPrices[i]);\\n                }\\n```\\n

Impact:
If the spot price is incorrect, it might potentially fail to detect the pool has been manipulated or result in unintended reverts due to false positives. In the worst-case scenario, the trade proceeds to execute against the manipulated pool, leading to a loss of assets.

Recommended mitigation:
Consider verifying if the comment of the `StableMath._calcSpotPrice` function is aligned with its implementation with the Balancer team.\\nIn addition, the `StableMath._calcSpotPrice` function is no longer used or found within the current version of Balancer's composable pool. Thus, there is no guarantee that the math within the `StableMath._calcSpotPrice` works with the current implementation. It is recommended to use the existing method in the current Composable Pool's StableMath, such as `_calcOutGivenIn` (ensure the fee is excluded) to compute the spot price.