Cri-o pods didn't provide sufficient isolation between the workload and infra containers such that when a workload consumed a large amount of memory, the kernel accidently killed the infra container's conmon process. An attacker would use the flaw to get host network access on an Kubernetes worker node.
Name: Nick Freeman (Capsule8)
Created cri-o tracking bugs for this issue:
Affects: fedora-all [bug 1774273]
As of cri-o v1.15 you can set conmon_cgroup = "system.slice" in the crio.runtime section of /etc/crio/crio.conf. On OpenShift Container Platform 4.x that can be done by following the documentation here:
For OpenShift Container Platform 3.x you can edit /etc/crio/crio.conf directly on the worker node if using cri-o on that version. Cri-o is not the default container engine on that version, Docker is.