The exploit ending in .flac works as a drive-by attack when a Fedora 25 user visits a booby-trapped webpage. With nothing more than a click required, the file will open the desktop calculator. With modification, it could load any code an attacker chooses and execute it with the same system privileges afforded to the user. While users typically don’t have the same unfettered system privileges granted to root, the ones they do have are plenty powerful.
Here’s a blurb from the researcher’s blog post about this:
Resolving all the above, I present here a full, working, reliable, 0day exploit for current Linux distributions (Ubuntu 16.04 LTS and Fedora 25). It’s a full drive-by download in the context of Fedora. It abuses cascading subtle side effects of an emulation misstep that at first appears extremely difficult to exploit but ends up presenting beautiful and 100% reliable exploitation possibilities.