Summary

The graduateAndUpgrade function authorizes an upgrade via _authorizeUpgrade(_levelTwo), but fails to perform the actual upgrade because _upgradeToAndCall is never called. As a result, the contract remains at the same implementation even after the function completes.

Vulnerability Details

In UUPS upgradeable contracts (like OpenZeppelin’s), the upgrade process typically involves two steps:

1. Authorization via _authorizeUpgrade(address newImplementation),

2. Execution via upgradeTo or upgradeToAndCall.

This function does only step 1:

But never calls:

_upgradeToAndCall(_levelTwo, data, false); // or true depending on use case

As a result, no upgrade actually takes place.

Impact

• The contract remains stuck on the current implementation.

• Any expected new logic or state from _levelTwo is never reached.

• Protocol misbehavior or stalling may occur due to false assumption that upgrade succeeded.