I thought about that. But when using a higher-level language (that comes with a runtime), you need to give privileges to the whole runtime, which arguably has a much bigger attack surface, unless I am mistaken?

The kernel won't allow you to setuid scripts, there is a reason for this: it's very easy to leave glaring security holes while doing so.

Perl had a fix for this called suidperl, which was a wrapper which enabled Taint mode and other strict checks (https://perldoc.perl.org/perlsec). I don't know of any other language or interpreter that go this far for security by default, so Perl might be the most secure language in this regard. However, suidperl was dropped in 5.12.

My main point was that you could rewrite sudo in all sorts of languages, but saying "just rewrite it in Perl" (assuming it worked) isn't a enough justification to make it happen. Nobody is going to re-create their own project in Perl, Rust, etc just to eliminate buffer overflows. If somebody wants sudo in Rust, they'll have to do it themselves, and it still might never replace the original.

Thank you for pointing that out :)

If someone would get serious about security, auditing every setuid binary would certainly be something on their list (if they use any). If they really want the functionality, rewriting it to cover just enough of the required functionality wouldn't be unheard of.

I agree. But really the security best practice is to remove setuid from all binaries, and rely on RBAC rules (such as with SELinux). That would solve more security issues than anything else, but this is way more effort than most people are willing to invest in security.