deth_ctf - codeHash check in deployVault does not correctly check for non-empty address, malicious user can self-destruct 1 wei to prevent an account from creating a vault forever.

[IkiliagwuC]

Description of the Bug: In the deployVault function users can deploy vaults to a computeAddress, a malicious user can compute anothers user's Vaultaddress, and forcefully(self-destruct) send 1 wei to the computed address to lock the user out of the protocol vault creation forever .

Because the check vaultAddress.codehash != bytes32(0) fails even if the vault has not been deployed but contains some ether(as little as 1 wei).

Impact: Users can be locked out of vault creation forever at very little expense by attacker(1 wei)

Solution: add this check if (vaultAddress.codehash != bytes32(0)) && vaultAddress.codehash != keccak256("") return VaultAlreadyDeployed;

[ghost]

The solution is not good. You should use || operator.

[0xdeth]

Duplicate of #9.