It was found that vdsm before version 4.20.37 invokes qemu-img on untrusted inputs without limiting resources. By uploading a specially crafted image, an attacker could cause the qemu-img process to consume unbounded amounts of memory of CPU time, causing a denial of service condition that could potentially impact other users of the host.
https://gerrit.ovirt.org/#/c/93195/
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-10908
https://access.redhat.com/errata/RHEA-2018:2624
http://lists.nongnu.org/archive/html/qemu-block/2018-07/msg00488.html