(Red Hat Issues Fix) Intel CPU Data Cache Race Conditions Let Local Users Read Arbitrary Virtual CPU Memory
SecurityTracker Alert ID: 1040085|
SecurityTracker URL: http://securitytracker.com/id/1040085
(Links to External Site)
Date: Jan 4 2018
Disclosure of system information|
Fix Available: Yes Vendor Confirmed: Yes Exploit Included: Yes |
Several vulnerabilities were reported in Intel, AMD, and ARM CPUs. A local user can read arbitrary virtual memory on the target CPU device.|
A local user can exploit race conditions in CPU data cache processing to obtain potentially sensitive information on the target system. This can be exploited to read arbitrary virtual memory on the target system, including by a local user on a guest operating system of a virtual machine to read arbitrary memory from other guest systems, the host operating system, and the hypervisor.
In certain cases, a local user can run a specially crafted application to exploit several flaws in the CPU speculative branch instruction execution feature and leverage CPU data cache timing behavior to infer information or read information from various CPU caches.
A local user that can trigger an out-of-bounds index error in an application can read data from another process from the CPU virtual memory [CVE-2017-5753]. The eBPF interpreter or the eBPF JIT engine can be used to create vulnerable code.
A local user can run specially crafted code to cause the CPU to speculatively execute an indirect branch to leak memory contents from another process into a CPU cache and then read the contents of the cache [CVE-2017-5715].
A local user can run specially crafted code to cause the CPU to read memory from a CPU cache before an asynchronous permission check occurs [CVE-2017-5754]. AMD CPUs are reportedly not affected.
The Intel Core, Xeon, Atom, Celeron, and Pentium product lines are affected.
CPUs from AMD and ARM are also affected.
CPUs from other vendors may also affected.
The CVE-2017-5753 and CVE-2017-5715 vulnerabilities are referred to as "Spectre".
The CVE-2017-5754 vulnerability is referred to as "Meltdown".
The original advisories are available at:
Paul Kocher, Daniel Genkin, Daniel Gruss, Werner Haas, Mike Hamburg, Moritz Lipp, Stefan Mangard, Thomas Prescher, Michael Schwarz, Yuval Yarom, Anders Fogh, Jann Horn, the Google Project Zero Team, and others reported these vulnerabilities.
A local user can view arbitrary virtual memory contents on the target CPU device [which can lead to elevated privileges on the target system].|
Red Hat has issued a fix for CVE-2017-5715 for linux-firmware.|
The Red Hat advisory is available at:
Vendor URL: access.redhat.com/errata/RHSA-2018:0015 (Links to External Site)
Access control error, State error|
|Underlying OS: Linux (Red Hat Enterprise)|
|Underlying OS Comments: 7.3|
This archive entry is a follow-up to the message listed below.|
Source Message Contents
Subject: [RHSA-2018:0015-01] Important: linux-firmware security update|
-----BEGIN PGP SIGNED MESSAGE-----
Red Hat Security Advisory
Synopsis: Important: linux-firmware security update
Advisory ID: RHSA-2018:0015-01
Product: Red Hat Enterprise Linux
Advisory URL: https://access.redhat.com/errata/RHSA-2018:0015
Issue date: 2018-01-04
An update for linux-firmware is now available for Red Hat Enterprise Linux
7.3 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.
2. Relevant releases/architectures:
Red Hat Enterprise Linux ComputeNode EUS (v. 7.3) - noarch
Red Hat Enterprise Linux Server EUS (v. 7.3) - noarch
The linux-firmware packages contain all of the firmware files that are
required by various devices to operate.
* An industry-wide issue was found in the way many modern microprocessor
designs have implemented speculative execution of instructions (a commonly
used performance optimization). There are three primary variants of the
issue which differ in the way the speculative execution can be exploited.
Variant CVE-2017-5715 triggers the speculative execution by utilizing
branch target injection. It relies on the presence of a precisely-defined
instruction sequence in the privileged code as well as the fact that memory
accesses may cause allocation 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 cross the syscall
and guest/host boundaries and read privileged memory by conducting targeted
cache side-channel attacks. (CVE-2017-5715)
Note: This is the microcode counterpart of the CVE-2017-5715 kernel
Red Hat would like to thank Google Project Zero for reporting this issue.
For details on how to apply this update, which includes the changes
described in this advisory, refer to:
5. Bugs fixed (https://bugzilla.redhat.com/):
1519780 - CVE-2017-5715 hw: cpu: speculative execution branch target injection
6. Package List:
Red Hat Enterprise Linux ComputeNode EUS (v. 7.3):
Red Hat Enterprise Linux Server EUS (v. 7.3):
These packages are GPG signed by Red Hat for security. Our key and
details on how to verify the signature are available from
The Red Hat security contact is <firstname.lastname@example.org>. More contact
details at https://access.redhat.com/security/team/contact/
Copyright 2018 Red Hat, Inc.
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