Solidity Attack Vector #11: No Address Zero Check

The 'Zero Address' (0x000...) is a special address in Ethereum. Accidentally sending tokens or Ether to this address results in the funds being permanently lost.

The Risk

Many functions that initialize an owner or a recipient don't check if the address provided is the zero address.

Fix

Always add a requirement for critical address inputs:

`solidity

require(_recipient != address(0), "Zero address not allowed");

`