util/virlog.c in libvirt does not properly determine the hostname on LXC container startup, which allows local guest OS users to bypass an intended container protection mechanism and execute arbitrary commands via a crafted NSS module.
https://access.redhat.com/errata/RHSA-2018:3113
https://www.debian.org/security/2018/dsa-4137
https://www.redhat.com/archives/libvir-list/2018-February/msg00239.html