Exploit does not require user interaction
"To the best of our knowledge, all systemd-based Linux distributions are vulnerable, but SUSE Linux Enterprise 15, openSUSE Leap 15.0, and Fedora 28 and 29 are not exploitable because their user space is compiled with GCC's -fstack-clash-protection," the
advisory reads.
All three bugs can be leveraged with no user interaction. One memory corruption is locally exploitable, while the other can be capitalized over the network.
The two memory corruption flaws are exploitable since systemd v201 and v230.