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CentOS 6 : kernel (CESA-2018:1651) (Spectre)

medium Nessus Plugin ID 109965

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Synopsis

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

Description

An update for kernel is now available for Red Hat Enterprise Linux 6.

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 kernel packages contain the Linux kernel, the core of any Linux operating system.

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 issue is present in hardware and cannot be fully fixed via software update. The updated kernel packages provide software side of the mitigation for this hardware issue. To be fully functional, up-to-date CPU microcode applied on the system is required. Please refer to References section for further information about this issue, CPU microcode requirements and the potential performance impact.

In this update mitigations for x86 (both 32 and 64 bit) architecture are provided.

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, an erroneous code in the x86 kexec system call path caused a memory corruption. As a consequence, the system became unresponsive with the following kernel stack trace :

'WARNING: CPU: 13 PID: 36409 at lib/list_debug.c:59
__list_del_entry+0xa1/0xd0 list_del corruption. prev->next should be ffffdd03fddeeca0, but was (null)'

This update ensures that the code does not corrupt memory. As a result, the operating system no longer hangs. (BZ#1573176)

Solution

Update the affected kernel packages.

See Also

http://www.nessus.org/u?bb0bc919

Plugin Details

Severity: Medium

ID: 109965

File Name: centos_RHSA-2018-1651.nasl

Version: 1.13

Type: local

Agent: unix

Published: 5/23/2018

Updated: 4/15/2021

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

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

CVSS v3

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:kernel-headers, cpe:/o:centos:centos:6, p-cpe:/a:centos:centos:kernel-debug, p-cpe:/a:centos:centos:kernel-abi-whitelists, p-cpe:/a:centos:centos:kernel-firmware, p-cpe:/a:centos:centos:perf, p-cpe:/a:centos:centos:python-perf, p-cpe:/a:centos:centos:kernel, p-cpe:/a:centos:centos:kernel-doc, p-cpe:/a:centos:centos:kernel-debug-devel, p-cpe:/a:centos:centos:kernel-devel

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: 5/22/2018

Vulnerability Publication Date: 5/22/2018

Reference Information

CVE: CVE-2018-3639

RHSA: 2018:1651