On a fresh installation of a third-party package including Joomla 3.4.1, there is no indication in the control panel of an available update, and Components/Joomla Update even explicltly claims that

You already have the latest Joomla! version, 3.4.1.

This is clearly wrong, because the latest release is currently 3.4.3.

The PHP configuration on this server disables allow_url_fopen. With it enabled, the available update to 3.4.3 is immediately detected and offered for installation.

I'm aware that I'm reporting a bug in an older version, but since it is inherently irreproducible in the current release, I thought I'd do it anyway.