CVE-2019-14850

Red Hat statement

Red Hat Virtualization Host includes nbdkit as a dependency of libguestfs, and uses it in p2v/v2v migrations. libguestfs uses nbdkit with a Unix domain socket only, so this vulnerability is not exposed to untrusted users. Red Hat Virtualization 4.2 EUS includes a vulnerable version of nbdkit, however it is used only on the Hypervisor with a Unix domain socket, so this vulnerability is not exposed to untrusted users.

Red Hat mitigation

This attack is only possible if nbdkit is configured with a plugin that does a lot of work in its initial .open() callback. Some examples that do a lot of work are nbdkit-ssh-plugin and nbdkit-guestfs-plugin. The nbdkit-memory-plugin is an example that does very little work, and thus is not subject to this vulnerability. Only attackers that can connect to the nbdkit service can exploit this vulnerability. If nbdkit is not exposed over TCP (eg, nbdkit -U), or is bound only to a private network interface, or is protected by firewall rules, the attack surface is correspondingly limited.