Submitted by WatchPug
The current design/implementation of freeTrial allows users to get full refund before the freeTrial ends. Plus, a user can transfer partial of their time to another user using shareKey.
This makes it possible for the attacker to steal from the protocol by transferring freeTrial time from multiple addresses to one address and adding up to expirationDuration and call refund to steal from the protocol.
Given:
The attacker can create two wallet addresses: Alice and Bob.
Consider disabling cancelAndRefund() for users who transferred time to another user.
julien51 (Unlock Protocol) confirmed and commented:
0xleastwood (judge) commented:
julien51 (Unlock Protocol) commented:
0xleastwood (judge) commented:
