Aave DIVA Wrapper

Summary

The AaveDIVAWrapperCore contract has a centralized control structure where a single owner has exclusive rights to claim all yield (interest) generated from user deposits. This creates a significant centralization risk, especially because users are subjected to trust this single entity with their investment returns, and if the owner's account is compromised, all accumulated yield would be lost.

Vulnerability Details

The contract implements an ownership model where a single address (owner) has exclusive control over yield management.
https://github.com/Cyfrin/2025-01-diva/blob/1b6543768c341c2334cdff87b6dd627ee2f62c89/contracts/src/AaveDIVAWrapperCore.sol#L19-L20
https://github.com/Cyfrin/2025-01-diva/blob/1b6543768c341c2334cdff87b6dd627ee2f62c89/contracts/src/AaveDIVAWrapperCore.sol#L52
https://github.com/Cyfrin/2025-01-diva/blob/1b6543768c341c2334cdff87b6dd627ee2f62c89/contracts/src/AaveDIVAWrapperCore.sol#L335-L353

The vulnerability exists because:

1. Only the owner can claim yield generated from user deposits

2. Users who deposit funds have no control over or access to the yield their deposits generate

3. The owner can direct the yield to any address they choose

Impact

The centralization of yield control creates several risks:

1. Financial Risk:

   • Users have no guaranteed access to the yield their deposits generate

   • If the owner's private key is compromised, all accumulated yield could be stolen

2. Trust Dependencies:

   • Users must trust the owner to:

     • Act honestly and not misappropriate funds

     • Maintain secure control of their private key

     • Manage yield in the best interest of users

3. Single Point of Failure:

   • The entire yield distribution system depends on one address

   • If the owner becomes unavailable or compromised, the yield management system could fail

Tools Used

Manual Review

Recommendations

To mitigate these centralization risks, we recommend implementing one or more of the following solutions:

1. Automated Yield Distribution System:

   • Implement a transparent system that automatically distributes yield to depositors

   • Allow users to claim their portion of yield directly without owner intervention

2. Multi-signature Control:

   • Replace single-owner control with a multi-signature system

   • Require multiple parties to approve yield-related actions

3. Time-locked Operations:

   • Add time delays for yield claims

   • Give users time to review and potentially contest large yield withdrawals

4. Governance System:

   • Transition to a DAO-based governance system

   • Allow stakeholders to vote on yield management decisions