Doesn't matter. A malicious sshd able to run commands arbitrary users can just run malicious commands as those users.
We'd need something more like a cryptographically attested setreuid() and execve() combination that would run only commands signed with the private key of the intended user. You'd want to use a shared clock or something to protect against replay attacks
We'd need something more like a cryptographically attested setreuid() and execve() combination that would run only commands signed with the private key of the intended user. You'd want to use a shared clock or something to protect against replay attacks