CentOS 7 : libvirt (CESA-2018:1997) (Spectre)

medium Nessus Plugin ID 110907


The remote CentOS host is missing one or more security updates.


An update for libvirt is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

The libvirt library contains a C API for managing and interacting with the virtualization capabilities of Linux and other operating systems.
In addition, libvirt provides tools for remote management of virtualized systems.

Security Fix(es) :

* An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of Load & Store instructions (a commonly used performance optimization). It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory read from address to which a recent memory write has occurred may see an older value and subsequently cause an update into the microprocessor's data cache even for speculatively executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use this flaw to read privileged memory by conducting targeted cache side-channel attacks. (CVE-2018-3639)

Note: This is the libvirt side of the CVE-2018-3639 mitigation that includes support for guests running on hosts with AMD processors.

Red Hat would like to thank Ken Johnson (Microsoft Security Response Center) and Jann Horn (Google Project Zero) for reporting this issue.

Bug Fix(es) :

* Previously, the virtlogd service logged redundant AVC denial errors when a guest virtual machine was started. With this update, the virtlogd service no longer attempts to send shutdown inhibition calls to systemd, which prevents the described errors from occurring.

* Prior to this update, guest virtual machine actions that use a python library in some cases failed and 'Hash operation not allowed during iteration' error messages were logged. Several redundant thread access checks have been removed, and the problem no longer occurs.

* The 'virsh capabilities' command previously displayed an inaccurate number of 4 KiB memory pages on systems with very large amounts of memory. This update optimizes the memory diagnostic mechanism to ensure memory page numbers are displayed correctly on such systems.


Update the affected libvirt packages.

See Also


Plugin Details

Severity: Medium

ID: 110907

File Name: centos_RHSA-2018-1997.nasl

Version: 1.7

Type: local

Agent: unix

Published: 7/5/2018

Updated: 4/15/2021

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Agentless Assessment, Nessus

Risk Information


Risk Factor: Medium

Score: 6.7


Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: CVE-2018-3639


Risk Factor: Medium

Base Score: 5.5

Temporal Score: 5

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:centos:centos:libvirt, p-cpe:/a:centos:centos:libvirt-admin, p-cpe:/a:centos:centos:libvirt-client, p-cpe:/a:centos:centos:libvirt-daemon, p-cpe:/a:centos:centos:libvirt-daemon-config-network, p-cpe:/a:centos:centos:libvirt-daemon-config-nwfilter, p-cpe:/a:centos:centos:libvirt-daemon-driver-interface, p-cpe:/a:centos:centos:libvirt-daemon-driver-lxc, p-cpe:/a:centos:centos:libvirt-daemon-driver-network, p-cpe:/a:centos:centos:libvirt-daemon-driver-nodedev, p-cpe:/a:centos:centos:libvirt-daemon-driver-nwfilter, p-cpe:/a:centos:centos:libvirt-daemon-driver-qemu, p-cpe:/a:centos:centos:libvirt-daemon-driver-secret, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-core, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-disk, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-gluster, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-iscsi, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-logical, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-mpath, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-rbd, p-cpe:/a:centos:centos:libvirt-daemon-driver-storage-scsi, p-cpe:/a:centos:centos:libvirt-daemon-kvm, p-cpe:/a:centos:centos:libvirt-daemon-lxc, p-cpe:/a:centos:centos:libvirt-devel, p-cpe:/a:centos:centos:libvirt-docs, p-cpe:/a:centos:centos:libvirt-libs, p-cpe:/a:centos:centos:libvirt-lock-sanlock, p-cpe:/a:centos:centos:libvirt-login-shell, p-cpe:/a:centos:centos:libvirt-nss, cpe:/o:centos:centos:7

Required KB Items: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 7/3/2018

Vulnerability Publication Date: 5/22/2018

Reference Information

CVE: CVE-2018-3639

RHSA: 2018:1997