Inheritable Smart Contract Wallet

Summary

The contract lacks event emissions for important state changes. Without proper logging, key actions like adding or removing beneficiaries, updating deadlines, and modifying ownership remain opaque, hindering transparency, auditing, and real-time monitoring.

Vulnerability Details

Critical state transitions occur throughout the contract without emitting events. For instance:

• Beneficiary Changes: Functions such as addBeneficiery and removeBeneficiary modify the beneficiary list without logging these changes.

• Inheritance Updates: The inherit function changes the ownership or sets the inheritance flag (isInherited) without notifying observers.

• Deadline Updates: The internal _setDeadline function, invoked after state-changing operations, updates a crucial timestamp without event logging.

• General State Mutations: Other functions that modify state variables (e.g., ownership, trustee appointments) also lack corresponding events.

Without events, off-chain systems and auditors cannot easily track or verify these changes, reducing transparency and the ability to react to potential issues.

Impact

• Reduced Transparency: Stakeholders and monitoring tools miss out on real-time logs of state changes, impacting trust.

• Auditing Difficulties: Without a reliable event log, reconstructing the history of state modifications during audits becomes problematic.

• Delayed Incident Response: In the event of malicious activity or errors, the absence of event logs may slow down detection and remediation efforts.

• Deviation from Best Practices: Not emitting events for key state changes violates Solidity best practices, which recommend logging such operations for clarity and traceability.

Tools Used

• Manual Code Review

Recommendations

1. Emit Events for State Changes:

   • For beneficiary modifications:

     event BeneficiaryAdded(address beneficiary);

     event BeneficiaryRemoved(address beneficiary);

     ​

   • For inheritance changes:

     event InheritanceStateChanged(bool isInherited);

     event OwnershipTransferred(address previousOwner, address newOwner);

     ​

   • For deadline updates:

     event DeadlineUpdated(uint256 newDeadline);

     ​

2. Standardize Naming Conventions: Adopt consistent and descriptive names for events to facilitate off-chain monitoring and analysis.

3. Document Event Emissions: Clearly document when and why each event is emitted to improve code clarity and aid future audits.

4. Integrate with Monitoring Tools: Use emitted events with off-chain monitoring systems (e.g., The Graph, Etherscan alerts) to track state changes in real-time.