Inheritable Smart Contract Wallet
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Submission Details
Severity: high
Invalid

Reentrancy Vulnerability in withdrawInheritedFunds Function

0xadwa

Summary

The withdrawInheritedFunds function is vulnerable to reentrancy attacks because it performs state-dependent logic after transferring funds. A malicious beneficiary can exploit this by re-entering the function during an Ether or ERC-20 token transfer, causing an unexpected flow of execution and potentially draining the contract.

Vulnerability Details

• The function loops over beneficiaries and sends them either Ether (call{value: amountPerBeneficiary}("")) or ERC-20 tokens (safeTransfer).

• If a beneficiary is a malicious contract, its fallback function can re-enter withdrawInheritedFunds before the loop completes.

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 {
uint256 assetAmountAvailable = IERC20(_asset).balanceOf(address(this));
uint256 amountPerBeneficiary = assetAmountAvailable / divisor;
for (uint256 i = 0; i < divisor; i++) {
IERC20(_asset).safeTransfer(beneficiaries[i], amountPerBeneficiary);
}
}
}

Impact

  • Loss of all funds in the contract, as a single malicious beneficiary can recursively withdraw multiple times before others get their share.

  • Unfair distribution, where a single attacker gets more than their fair share of the inheritance.

Tools Used

Manual review

Recommendations

Use Reentrancy Guards

Add OpenZeppelin’s nonReentrant modifier to prevent recursive calls:

function withdrawInheritedFunds(address _asset) external nonReentrant {
Updates

Lead Judging Commences

0xtimefliez Lead Judge 9 months ago
Submission Judgement Published
Invalidated
Reason: Incorrect statement

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