Submission Details
Impact:
Likelihood:
Lack of Input Validation (Overflow/Underflow on Mint)
Problem:
No checks on the value parameter in mint.
If value is extremely large, value * 10 ** updateDecimals can overflow, even in Solidity 0.8.x (which reverts on overflow, but still leads to DoS).
Risk:
Attacker can cause mint to revert for all users by passing a value that overflows.
Potential for DoS or protocol disruption.
function mint(address to, uint256 value) public {
uint256 updateDecimals = uint256(tokenDecimals);
_mint(to, (value * 10 ** updateDecimals));
}
Proof of Concept
function testMintOverflow() public {
MockUSDC token = new MockUSDC(18);
// This will revert due to overflow
token.mint(address(this), type(uint256).max);
}
Recommended Mitigation
function mint(address to, uint256 value) public onlyOwner {
- uint256 updateDecimals = uint256(tokenDecimals);
- _mint(to, (value * 10 ** updateDecimals));
+ uint256 updateDecimals = uint256(tokenDecimals);
+ require(value <= type(uint256).max / (10 ** updateDecimals), "Overflow");
+ _mint(to, (value * 10 ** updateDecimals));
}
Updates
Rewards breakdown
nSLOC
217This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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