Inheritable Smart Contract Wallet

Summary

Beneficiaries can gain trustee privileges, manipulate asset values, and permanently destroy all NFTs

Vulnerability Details

Any beneficiary can be appointed as trustee via appointTrustee() after inheritance is triggered. Once trustee, they gain access to critical functions like setNftValue() and setAssetToPay()

Any beneficiary can:
set NFT values to near-zero using setNftValue()

set payment token to one they control via setAssetToPay()

call buyOutEstateNFT() at minimal cost

NFTs are permanently burned by nft.burnEstate(_nftID)

Impact

Every beneficiary can destroy all NFTs will almost no cost.

Tools Used

Manual code review

Recommendations

Implement voting mechanism for appointing trustee.

Add requirements to setNftValue() like minimal value.

Create whitelist for tokens that can be used in setAssetToPay().