Inheritable Smart Contract Wallet

Summary - The InheritanceManager.sol::onlyBeneficiaryWithIsInherited modifier improperly checks the upper boundary of the beneficiaries array, potentially leading to an out-of-bounds array access. This vulnerability could result in unexpected contract behavior or runtime exceptions.

Vulnerability Details - The onlyBeneficiaryWithIsInherited modifier is intended to verify if the msg.sender is a beneficiary and if the isInherited flag is set to true. However, the while loop condition incorrectly checks:

In Solidity, arrays are zero-indexed, meaning valid indices range from 0 to beneficiaries.length - 1. The current implementation extends the loop one step beyond the valid range, causing an out-of-bounds access when the index i reaches beneficiaries.length. This results in a runtime panic with error code 0x32 (array out-of-bounds access).

The output of this test:

Impact

Exploiting this vulnerability will cause the contract to revert with an out-of-bounds panic, preventing intended contract execution. This could block critical functionality for authorized beneficiaries, especially in inheritance-related scenarios.

Tools Used

• Manual Review

Recommendations

• Modify the loop boundary condition to correctly iterate within the valid range of the array: