Summary

The buyOutEstateNFT function in InheritanceManager.sol miscalculates the amount to be paid by the buyer. The function first removes the buyer’s share using a multiplier but still divides the final amount by the total number of beneficiaries (divisor), causing underpayment to the remaining beneficiaries.

Vulnerability Details

The function removes msg.sender's share using multiplier = beneficiaries.length - 1.

• However, later in the function, finalAmount is still divided by divisor instead of multiplier, reducing the payout to each beneficiary.

Impact

• Underpayment of beneficiaries: Each remaining beneficiary receives less than their fair share.

• Discrepancy in fund distribution: The contract does not distribute the expected total amount, leading to potential disputes.

Tools Used

• Foundry tests (to verify discrepancies in expected balances)

• console.log to monitor balance

Recommendations

Modify the final amount calculation to ensure it is divided by the correct multiplier instead of divisor: