Submission Details
Severity:
Known vulnerabilities of ERC-20 token, contract `DecentralizedStableCoin.sol`
Double withdrawal attack is possible.(https://docs.google.com/document/d/1YLPtQxZu1UAvO9cZ1O2RPXBbT0mooh4DYKjA_jp-RLM/edit)
The contract lacks a proper transaction handling mechanism, particularly for contracts without a fallback mechanism.(https://gist.github.com/Dexaran/ddb3e89fe64bf2e06ed15fbd5679bd20)
Recommendation:
For the first issue, a robust solution is to reimplement the approve function by comparing current allowance for spender with the current Value:
File: DecentralizedStableCoin.sol
function approve(address spender,
uint256 _currentValue
uint256 amount) public internal override returns (bool) {
if(_allowances[owner][spender] == _currentValue){
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
else {
return false;
}
}
For the second issue, add the following code to the transfer(_to address, ...) function:
File: DecentralizedStableCoin.sol
require( _to != address(this) );
Prize pool breakdown
Total prize
15,000 USDC
nSLOC
23664 USDC / LOC
14,000 USDC
1,000 USDC
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