A vulnerability was found in libvirt, where an incorrect permissions on the UNIX domain socket. A local attacker could use this issue to access libvirt and escalate privileges.
Created libvirt tracking bugs for this issue:
Affects: fedora-all [bug 1866271]
Created mingw-libvirt tracking bugs for this issue:
Affects: fedora-all [bug 1866272]
This is an Ubuntu specific flaw because they change the libvirt defaults in their distro to disable use of polkit for authentication, without also changing the socket permissisons.
The normal upstream behaviour is that the socket is mode 0666, and when an unprivileged user connects, polkit will validate the client and require them to provide the root password before libvirt allows any RPC calls to be performed.
RHEL/Fedora follow this upstram behaviour and use polkit for auth, so there is no security flaw here.
This is an Ubuntu specific flaw. The versions of `libvirt` as shipped with Red Hat Enterprise Linux and RHEL Advanced Virtualization are not affected by this issue, as they leverage `polkit` for authentication. More specifically, the socket permission is 0666, and when an unprivileged user connects, `polkit` will validate the client and require them to provide the root password before `libvirt` allows any RPC calls to be performed.