Spectre and Meltdown don't give you the ability to _write_ memory, only _read_ it. So they're "only" a problem to the extent that there is information you do n

Spectre and Meltdown don't give you the ability to _write_ memory, only _read_ it. So they're "only" a problem to the extent that there is information you do not want the attacker to read. Passwords are the first obvious target here. Of course the same attack could expose other credentials, so it's not a password-specific issue.