Synopsis

Important: redhat-virtualization-host security update

Type/Severity

Security Advisory: Important

Topic

An update for redhat-release-virtualization-host and redhat-virtualization-host is now available for Red Hat Virtualization 4 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.

Description

The redhat-virtualization-host packages provide the Red Hat Virtualization Host. These packages include redhat-release-virtualization-host, ovirt-node, and rhev-hypervisor. Red Hat Virtualization Hosts (RHVH) are installed using a special build of Red Hat Enterprise Linux with only the packages required to host virtual machines. RHVH features a Cockpit user interface for monitoring the host's resources and performing administrative tasks.

The ovirt-node-ng packages provide the Red Hat Virtualization Host. These packages include redhat-release-virtualization-host, ovirt-node, and rhev-hypervisor. Red Hat Virtualization Hosts (RHVH) are installed using a special build of Red Hat Enterprise Linux with only the packages required to host virtual machines. RHVH features a Cockpit user interface for monitoring the host's resources and performing administrative tasks.

Security Fix(es):

• A flaw was found in the implementation of the "fill buffer", a mechanism used by modern CPUs when a cache-miss is made on L1 CPU cache. If an attacker can generate a load operation that would create a page fault, the execution will continue speculatively with incorrect data from the fill buffer while the data is fetched from higher level caches. This response time can be measured to infer data in the fill buffer. (CVE-2018-12130)
  
• Modern Intel microprocessors implement hardware-level micro-optimizations to improve the performance of writing data back to CPU caches. The write operation is split into STA (STore Address) and STD (STore Data) sub-operations. These sub-operations allow the processor to hand-off address generation logic into these sub-operations for optimized writes. Both of these sub-operations write to a shared distributed processor structure called the 'processor store buffer'. As a result, an unprivileged attacker could use this flaw to read private data resident within the CPU's processor store buffer. (CVE-2018-12126)
  
• Microprocessors use a ‘load port’ subcomponent to perform load operations from memory or IO. During a load operation, the load port receives data from the memory or IO subsystem and then provides the data to the CPU registers and operations in the CPU’s pipelines. Stale load operations results are stored in the 'load port' table until overwritten by newer operations. Certain load-port operations triggered by an attacker can be used to reveal data about previous stale requests leaking data back to the attacker via a timing side-channel. (CVE-2018-12127)
  
• Uncacheable memory on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. (CVE-2019-11091)
  

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/2974891

Affected Products

• Red Hat Virtualization 4 for RHEL 7 x86_64
• Red Hat Virtualization Host 4 x86_64

Fixes

• BZ - 1646781 - CVE-2018-12126 hardware: Microarchitectural Store Buffer Data Sampling (MSBDS)
• BZ - 1646784 - CVE-2018-12130 hardware: Microarchitectural Fill Buffer Data Sampling (MFBDS)
• BZ - 1667782 - CVE-2018-12127 hardware: Micro-architectural Load Port Data Sampling - Information Leak (MLPDS)
• BZ - 1705312 - CVE-2019-11091 hardware: Microarchitectural Data Sampling Uncacheable Memory (MDSUM)

CVEs

• CVE-2018-12126
• CVE-2018-12127
• CVE-2018-12130
• CVE-2019-11091

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/security/vulnerabilities/mds

Red Hat Virtualization 4 for RHEL 7

SRPM
redhat-release-virtualization-host-4.3-0.7.el7.src.rpm	SHA-256: dc48a15e90a3b58bdc9acf7d1510d35b3ec3b6976904624ca1e3afc65362e078
x86_64
redhat-release-virtualization-host-4.3-0.7.el7.x86_64.rpm	SHA-256: 9a198827369a97426a092163e53a94e3ae9cf44e853d67b2a9450b64dc932d9a
redhat-virtualization-host-image-update-placeholder-4.3-0.7.el7.noarch.rpm	SHA-256: 9b77afaf2cf4286e2b05640f33207f3ccf71e5f7b0fa383b99c65fb87a53f379

Red Hat Virtualization Host 4

SRPM
redhat-virtualization-host-4.3-20190512.0.el7_6.src.rpm	SHA-256: e404cbab2b4f2b5b3e1f4ea164f2f025e9a871cf59bb479dc362282523248cc9
x86_64
redhat-virtualization-host-image-update-4.3-20190512.0.el7_6.noarch.rpm	SHA-256: 2d1e9a1bfd8cfed27121fb1b36b83a17fdad34a912b615b0b11f56648939553a