RHEL 6 : libvirt (RHSA-2018:3400) (Spectre)
Medium Nessus Plugin ID 118549
Synopsis
The remote Red Hat host is missing one or more security updates.
Description
An update for libvirt is now available for Red Hat Enterprise Linux 6.6 Advanced Update Support and Red Hat Enterprise Linux 6.6 Telco Extended Update Support.
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 virt-ssbd AMD)
Note: This is the libvirt side of the CVE-2018-3639 mitigation.
Red Hat would like to thank Ken Johnson (Microsoft Security Response Center) and Jann Horn (Google Project Zero) for reporting this issue.
Solution
Update the affected packages.