Lines of code

https://github.com/code-423n4/2024-07-basin/blob/main/src/functions/Stable2.sol#L74-L103

Vulnerability details

Description

In the calcLpTokenSupply function, there is a potential integer overflow/underflow vulnerability due to arithmetic operations involving large numbers. Integer overflow/underflow can lead to unexpected results, such as incorrect calculations or unintended contract behavior. This issue occurs in the loop where arithmetic operations are performed on lpTokenSupply, which can lead to values exceeding the maximum or minimum limits of the uint256 type.

Impact

If an integer overflow or underflow occurs, the calculations within the calcLpTokenSupply function may produce incorrect results. This can lead to incorrect lpTokenSupply values, which in turn may affect the overall functionality of the contract, including potential financial losses or unintended behavior.

Proof of Concept

Here is a simplified PoC to demonstrate how an integer overflow/underflow could occur:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "forge-std/Test.sol";
import "../src/Stable2.sol";

contract OverflowTest is Test {
    Stable2 stable2;

    address constant LOOKUP_TABLE_ADDRESS = 0x...; // Replace with the appropriate lookupTable address

    function setUp() public {
        stable2 = new Stable2(LOOKUP_TABLE_ADDRESS);
    }

    function testIntegerOverflow() public {
        uint256[] memory reserves = new uint256[](2);
        reserves[0] = type(uint256).max;
        reserves[1] = type(uint256).max;

        bytes memory data = abi.encode(18, 18);

        // Attempt to cause overflow
        stable2.calcLpTokenSupply(reserves, data);
    }
}

Tools Used

manual review

Recommended Mitigation Steps

To mitigate this issue:

Use SafeMath Library: Incorporate the SafeMath library to perform arithmetic operations safely. SafeMath provides functions for addition, subtraction, multiplication, and division that revert on overflow or underflow.

import "@openzeppelin/contracts/utils/math/SafeMath.sol";

// Example usage in the function using SafeMath for uint256; Check for Overflow/Underflow Manually: Add checks before performing arithmetic operations to ensure values are within safe limits.

require(lpTokenSupply <= type(uint256).max / (scaledReserves[0] * N), "Overflow detected");
Testing and Auditing: Conduct thorough testing and auditing of arithmetic operations in your contract to ensure that no overflow or underflow scenarios exist.

Use Latest Compiler Version: Ensure you are using the latest version of the Solidity compiler, as newer versions may include built-in protections against such vulnerabilities.

Assessed type

Under/Overflow

code-423n4 / 2024-07-basin-validation

In the ``Stable2`` contract ``calcLpTokenSupply‍‍`` function, there is a potential integer overflow/underflow vulnerability #32