Summary

Insufficient token balance on L2 will lead to no token minting on L2 for the corresponding bridge request on L1 even though the L1BossBridge::L1BossBridge txn was successful.

Vulnerability Details

When a user bridges token by L1BossBridge::L1BossBridge, an event is triggered which off-chain mechanism picks up, and mints the corresponding tokens on L2 but if in case the balance is less than the deposited amount, so there will be no minting of tokens on L2 as a result of which the request will be bounced and user will receive no funds.

Impact

User can't withdraw the bridged tokens on the other layer.

Tools Used

Manual Review

Recommendations

To only allow user to deposit if there are sufficient funds.