Inheritable Smart Contract Wallet
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Submission Details
Severity: high
Invalid

Missing reentrancy protection in withdrawInheritedFunds allows DOS attack blocking inheritance distribution

anchabadze

Description:

The withdrawInheritedFunds() function in InheritanceManager contract lacks reentrancy protection, making it vulnerable to Denial of Service (DOS) attacks from malicious beneficiaries. The contract does have a nonReentrant` modifier, but it's incorrectly implemented and not applied to this critical function:

// Vulnerable function without reentrancy protection
function withdrawInheritedFunds(address _asset) external {
if (!isInherited) {
revert NotYetInherited();
}
uint256 divisor = beneficiaries.length;
if (_asset == address(0)) {
uint256 ethAmountAvailable = address(this).balance;
uint256 amountPerBeneficiary = ethAmountAvailable / divisor;
for (uint256 i = 0; i < divisor; i++) {
address payable beneficiary = payable(beneficiaries[i]);
(bool success,) = beneficiary.call{value: amountPerBeneficiary}("");
require(success, "something went wrong");
}
} else {
// ERC20 token distribution code...
}
}

The function iterates through beneficiaries and makes external calls to each one when distributing ETH. Since these calls are made before completing the function, a malicious contract as a beneficiary can launch a DOS attack by consuming all gas in its receive() function, causing the entire transaction to fail.

Impact:

A malicious beneficiary can prevent ANY distribution of assets to legitimate beneficiaries by making the transaction revert. Permanent denial of service: Since the list of beneficiaries cannot be modified after inheritance is activated (isInherited = true), a single malicious actor can permanently block the core functionality of the contract. The primary purpose of this contract (asset inheritance) becomes impossible to fulfill.

Recommended Mitigation:

Apply the nonReentrant modifier. But first you need to fix the existing nonReentrant modifier, because in the current implementation it's broke

Updates

Lead Judging Commences

0xtimefliez Lead Judge 6 months ago
Submission Judgement Published
Invalidated
Reason: Incorrect statement

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