Tuned: `script_pre` and `script_post` options allow to pass arbitrary scripts executed by root

A script injection vulnerability was identified in the Tuned package. The `instance_create()` D-Bus function can be called by locally logged-in users without authentication. This flaw allows a local non-privileged user to execute a D-Bus call with `script_pre` or `script_post` options that permit arbitrary scripts with their absolute paths to be passed. These user or attacker-controlled executable scripts or programs could then be executed by Tuned with root privileges that could allow attackers to local privilege escalation.