Eggstravaganza

Summary

The endTime variable is defined and set during the game start, but its enforcement is inconsistent across the contract. While some functions (like searchForEgg) include a check for endTime, others (like depositEggToVault) do not. This inconsistency allows for scenarios where the game appears to have ended but players can still interact with certain functions, leading to:

1. Inconsistent Game State: Some functions enforce endTime, while others rely solely on gameActive.

2. Unfair Gameplay: Players can deposit eggs or perform other actions after the game has logically ended.

3. Economic and Trust Issues: Rewards or incentives tied to the game's lifecycle may be exploited or misaligned.

Vulnerability Details

1/ searchForEgg Enforces endTime

The searchForEgg function includes a check for endTime:

This ensures that players cannot search for eggs after the game has ended.

2/ depositEggToVault Does NOT Enforce endTime

The depositEggToVault function does not check endTime:

This allows players to deposit eggs into the vault even after the game has ended, creating inconsistencies in the game's lifecycle.

3/ endGame Relies on Manual Intervention

The endGame function must be called manually by the owner to stop the game:

If the owner forgets or is unavailable to call this function, the game can continue indefinitely, even though endTime has passed.

4/ getGameStatus Reflects endTime but Does Not Enforce It. this is purely informational and does not enforce endTime in any way.

Impact

Inconsistent Enforcement:

Players can still deposit eggs after the game has ended, creating inconsistencies in the game's lifecycle.
Unfair Advantage:

Players who deposit eggs after the game has ended could gain an unfair advantage in tournaments or reward systems.
Economic Exploitation:

If rewards are tied to deposits or other actions, players could exploit the lack of endTime enforcement to claim rewards after the game has ended.
Centralization Risk:

The reliance on the owner to manually call endGame introduces a centralization risk. If the owner is unavailable, the game can continue indefinitely.

Tools Used

manual review

Recommendations

Option 1: Enforce endTime in all critical functions

Option 2: Automatically end the game when endTime is reached - could be done with oracle feeds and a keeper.