RHEL 6 : kernel (RHSA-2018:2390)

high Nessus Plugin ID 111731

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Synopsis

The remote Red Hat host is missing one or more security updates for kernel.

Description

The remote Redhat Enterprise Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2018:2390 advisory.

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

Security Fix(es):

* Modern operating systems implement virtualization of physical memory to efficiently use available system resources and provide inter-domain protection through access control and isolation. The L1TF issue was found in the way the x86 microprocessor designs have implemented speculative execution of instructions (a commonly used performance optimisation) in combination with handling of page-faults caused by terminated virtual to physical address resolving process. As a result, an unprivileged attacker could use this flaw to read privileged memory of the kernel or other processes and/or cross guest/host boundaries to read host memory by conducting targeted cache side-channel attacks. (CVE-2018-3620, CVE-2018-3646)

* An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of instructions past bounds check. The flaw relies on the presence of a precisely- defined instruction sequence in the privileged code and the fact that memory writes occur to an address which depends on the untrusted value. Such writes 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 influence speculative execution and/or read privileged memory by conducting targeted cache side-channel attacks. (CVE-2018-3693)

* A flaw named SegmentSmack was found in the way the Linux kernel handled specially crafted TCP packets. A remote attacker could use this flaw to trigger time and calculation expensive calls to tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() functions by sending specially modified packets within ongoing TCP sessions which could lead to a CPU saturation and hence a denial of service on the system.
Maintaining the denial of service condition requires continuous two-way TCP sessions to a reachable open port, thus the attacks cannot be performed using spoofed IP addresses. (CVE-2018-5390)

* kernel: kvm: vmx: host GDT limit corruption (CVE-2018-10901)

* kernel: Use-after-free in snd_pcm_info function in ALSA subsystem potentially leads to privilege escalation (CVE-2017-0861)

* kernel: Use-after-free in snd_seq_ioctl_create_port() (CVE-2017-15265)

* kernel: race condition in snd_seq_write() may lead to UAF or OOB-access (CVE-2018-7566)

* kernel: Race condition in sound system can lead to denial of service (CVE-2018-1000004)

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

Red Hat would like to thank Intel OSSIRT (Intel.com) for reporting CVE-2018-3620 and CVE-2018-3646;
Vladimir Kiriansky (MIT) and Carl Waldspurger (Carl Waldspurger Consulting) for reporting CVE-2018-3693;
Juha-Matti Tilli (Aalto University, Department of Communications and Networking and Nokia Bell Labs) for reporting CVE-2018-5390; and Vegard Nossum (Oracle Corporation) for reporting CVE-2018-10901.

Bug Fix(es):

* The Least recently used (LRU) operations are batched by caching pages in per-cpu page vectors to prevent contention of the heavily used lru_lock spinlock. The page vectors can hold even the compound pages.
Previously, the page vectors were cleared only if they were full. Subsequently, the amount of memory held in page vectors, which is not reclaimable, was sometimes too high. Consequently the page reclamation started the Out of Memory (OOM) killing processes. With this update, the underlying source code has been fixed to clear LRU page vectors each time when a compound page is added to them. As a result, OOM killing processes due to high amounts of memory held in page vectors no longer occur. (BZ#1575819)

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL kernel package based on the guidance in RHSA-2018:2390.

Plugin Details

Severity: High

ID: 111731

File Name: redhat-RHSA-2018-2390.nasl

Version: 1.15

Type: local

Agent: unix

Family: Red Hat Local Security Checks

Published: 8/15/2018

Updated: 11/5/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.6

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

CVSS Score Source: CVE-2018-10901

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

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

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

CVSS Score Source: CVE-2018-7566

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-headers, p-cpe:/a:redhat:enterprise_linux:kernel-firmware, cpe:/o:redhat:enterprise_linux:6, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-kdump, p-cpe:/a:redhat:enterprise_linux:kernel-bootwrapper, p-cpe:/a:redhat:enterprise_linux:python-perf, p-cpe:/a:redhat:enterprise_linux:kernel-kdump-devel, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:perf

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/16/2018

Vulnerability Publication Date: 10/16/2017

Reference Information

CVE: CVE-2017-0861, CVE-2017-15265, CVE-2018-1000004, CVE-2018-10901, CVE-2018-3620, CVE-2018-3646, CVE-2018-3693, CVE-2018-5390, CVE-2018-7566

CWE: 200, 362, 400, 416, 665

RHSA: 2018:2390

Detections

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