AddressZero

Very bad things would happen if you could set msg.sender to address(0) during actual execution. The Optimism bridge would be susceptible to attack. The exploit is very simple, see src/AddressZero.sol.

Run the exploit like so:

$ forge script \
    -vvvvv src/AddressZero.sol \
    --tc AddressZero \
    --rpc-url <mainnet-url>