Possible Bugs, Vulnerabilities & Potential Exploits

[nikhilsurfingaus]

Compiler Issue (Risk: Medium)

Smart contract is defined using the ^ operator for compiler version.

Resolve

Best practice to use static rather than dynamic compiler version as future versions could have unintended effects

pragma solidity ^0.8.0;

Proposed Solution

pragma solidity 0.8.0;

Overflow/Underflow Issue (Risk: Low)

Loop Integer Overflow/Underflow Bug Detected

Resolve

When using uint for/while loop avoid >= or <= that could cause infinite loop. Instead use >, <, == or != loop operators. Careful when using uint within loop as could cause infinite loop check no constant true condition can evaluate.

        for (uint i = 0; i < len && i <= 2; i++) {
            addresses[i] = _stakers[i].wallet;
            amounts[i] = _stakers[i].amount;
        }
        for (uint i = startIndex; i <= endIndex && i < _stakers.length; i++) {
            totalAmount +=  _stakers[i].amount;
        }
        for (uint256 i= currentIndex ; i < _stakers.length-1 ; i++) {
            _stakers[i] = _stakers[i+1];
            _stakers[i].index_at = _stakers[i].index_at.sub(1);
            _indexStaker[_stakers[i].wallet] = _stakers[i].index_at;
        }

Overflow/Underflow Issue (Risk: Medium)

Integer Overflow/Underflow Bug Detected

Resolve

Use SafeMath library operation .mul, .sub, .add, .div to minimise vulnerbaility

        _apyStruct = GraphLinqApyStruct(50*1e18, 25*1e18, 12500000000000000000);
        GlqStaker storage staker = _stakers[index - 1];

        uint256 _numerator  = numerator * 10 ** (precision+1);
        uint256 _quotient =  ((_numerator / denominator) + 5) / 10;

Block Gas Limit Bug (Risk: Medium)

Avoid loop of unknown size that could grow and cause DoS vulnerability

Resolve

        for (uint i = startIndex; i <= endIndex && i < _stakers.length; i++) {
            totalAmount +=  _stakers[i].amount;
        }        

        for (uint256 i= currentIndex ; i < _stakers.length-1 ; i++) {
            _stakers[i] = _stakers[i+1];
            _stakers[i].index_at = _stakers[i].index_at.sub(1);
            _indexStaker[_stakers[i].wallet] = _stakers[i].index_at;
        }

Zero Address Check Bug (Risk: Low)

Check address is not zero using require, address variable and checking it is not equal to either 'address(0)', '0x0' or 'address(0x0)'