This seems to be a nasty Linux vulnerability. This vulnerability has been in plain sight 12+ years. Lucky for most there are patches available so be sure to get ahead of this issue and updates those systems.
The Qualys Research Team has discovered a memory corruption vulnerability in polkit’s pkexec, a SUID-root program that is installed by default on every major Linux distribution. This easily exploited vulnerability allows any unprivileged user to gain full root privileges on a vulnerable host by exploiting this vulnerability in its default configuration.
To see this exploit in action view this video from Qualys.