ERC20Vault

This erc20 vault is a trusted vault that has just added support for a new ERC20 token WETH. My grandma is about to deposit her life savings of WETH into to the vault. Can you hack the contract and report the bug to the vault owners?

Save my grandma's WETH by proving there is a bug in the ERC20Vault contract.

Author: IzuMan

Hints: What happens when you call a contract with a selector that doesn't match any in the contract?