Other way around. This requires a passwordless account configured with sha256 or sha512 password hash, musl system with openssh installed, no PAM, and password authentication allowed:
When logging into a passwordless account, the attacker can gain access by inputting more than 256 characters in the password field.
This particular vulnerability is precisely about logins with key. Using password login renders this vulnerability useless.
Other way around. This requires a passwordless account configured with sha256 or sha512 password hash, musl system with openssh installed, no PAM, and password authentication allowed: