It was discovered that libvirtd would permit readonly clients to use the virDomainManagedSaveDefineXML() API, which would permit them to modify managed save state files. If a managed save had already been created by a privileged user, a local attacker could modify this file such that libvirtd would execute an arbitrary program when the domain was resumed. This vulnerability was first present in libvirt v3.6.1.
Statement: * This vulnerability requires access to the libvirt socket, normally in /var/run/libvirt/libvirt_sock_ro. Typically in hypervisor environments, local user accounts are not supported so no untrusted users should be able to access this socket. * Red Hat Gluster Storage 3 is not affected by this vulnerability as libvirtd daemon is not shipped in Gluster.
External References: https://access.redhat.com/libvirt-privesc-vulnerabilities
Mitigation: The Unix permissions of libvirt's read-only socket can be made more restrictive than the default (0777) by editing `/etc/libvirt/libvirtd.conf`. The settings `unix_sock_group = libvirt` and `unix_sock_ro_perms = 0770` will restrict access to only members of `libvirt`, who already have management access to virtual machines.
Upstream patch: https://libvirt.org/git/?p=libvirt.git;a=commit;h=db0b78457f183e4c7ac45bc94de86044a1e2056a
Created libvirt tracking bugs for this issue: Affects: fedora-all [bug 1722462] Created mingw-libvirt tracking bugs for this issue: Affects: fedora-all [bug 1722465]
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2019:1579 https://access.redhat.com/errata/RHSA-2019:1579
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2019:1580 https://access.redhat.com/errata/RHSA-2019:1580
Acknowledgments: Name: Matthias Gerstner (SUSE)
This issue has been addressed in the following products: Red Hat Virtualization 4 for Red Hat Enterprise Linux 7 Via RHSA-2019:1699 https://access.redhat.com/errata/RHSA-2019:1699
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Advanced Virtualization Via RHSA-2019:1762 https://access.redhat.com/errata/RHSA-2019:1762
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2019-10166