RHEL 6 : kernel (RHSA-2018:2933)

high Nessus Plugin ID 118165
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

Synopsis

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

Description

An update for kernel is now available for Red Hat Enterprise Linux 6.5 Advanced 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 kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es) :

* 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)

* A flaw named FragmentSmack was found in the way the Linux kernel handled reassembly of fragmented IPv4 and IPv6 packets. A remote attacker could use this flaw to trigger time and calculation expensive fragment reassembly algorithm by sending specially crafted packets which could lead to a CPU saturation and hence a denial of service on the system. (CVE-2018-5391)

* kernel: mm: use-after-free in do_get_mempolicy function allows local DoS or other unspecified impact (CVE-2018-10675)

* kernel: Integer overflow in Linux's create_elf_tables function (CVE-2018-14634)

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 Juha-Matti Tilli (Aalto University - Department of Communications and Networking and Nokia Bell Labs) for reporting CVE-2018-5390 and CVE-2018-5391 and Qualys Research Labs for reporting CVE-2018-14634.

Bug Fix(es) :

* Previously, invalid headers in the sk_buff struct led to an indefinite loop in the tcp_collapse() function. As a consequence, the system became unresponsive. This update backports the upstream changes that remove the problematic code in tcp_collapse(). As a result, the system no longer hangs in the described scenario. (BZ#1619630)

* After updating the system to prevent the L1 Terminal Fault (L1TF) vulnerability, only one thread was detected on systems that offer processing of two threads on a single processor core. With this update, the '__max_smt_threads()' function has been fixed. As a result, both threads are now detected correctly in the described situation. (BZ#1625333)

* Previously, a kernel panic occurred when the kernel tried to make an out of bound access to the array that describes the L1 Terminal Fault (L1TF) mitigation state on systems without Extended Page Tables (EPT) support. This update extends the array of mitigation states to cover all the states, which effectively prevents out of bound array access.
Also, this update enables rejecting invalid, irrelevant values, that might be erroneously provided by the userspace. As a result, the kernel no longer panics in the described scenario. (BZ#1629632)

Solution

Update the affected packages.

See Also

https://access.redhat.com/articles/3553061

https://access.redhat.com/security/vulnerabilities/mutagen-astronomy

https://access.redhat.com/errata/RHSA-2018:2933

https://access.redhat.com/security/cve/cve-2018-5390

https://access.redhat.com/security/cve/cve-2018-5391

https://access.redhat.com/security/cve/cve-2018-10675

https://access.redhat.com/security/cve/cve-2018-14634

Plugin Details

Severity: High

ID: 118165

File Name: redhat-RHSA-2018-2933.nasl

Version: 1.9

Type: local

Agent: unix

Published: 10/17/2018

Updated: 10/24/2019

Dependencies: ssh_get_info.nasl, linux_alt_patch_detect.nasl

Risk Information

VPR

Risk Factor: High

Score: 8.4

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.1

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

Temporal Vector: E:POC/RL:OF/RC:C

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: E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-abi-whitelists, p-cpe:/a:redhat:enterprise_linux:kernel-debug, p-cpe:/a:redhat:enterprise_linux:kernel-debug-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel, p-cpe:/a:redhat:enterprise_linux:kernel-debuginfo, p-cpe:/a:redhat:enterprise_linux:kernel-debuginfo-common-x86_64, p-cpe:/a:redhat:enterprise_linux:kernel-devel, p-cpe:/a:redhat:enterprise_linux:kernel-doc, p-cpe:/a:redhat:enterprise_linux:kernel-firmware, p-cpe:/a:redhat:enterprise_linux:kernel-headers, p-cpe:/a:redhat:enterprise_linux:perf, p-cpe:/a:redhat:enterprise_linux:perf-debuginfo, p-cpe:/a:redhat:enterprise_linux:python-perf, p-cpe:/a:redhat:enterprise_linux:python-perf-debuginfo, cpe:/o:redhat:enterprise_linux:6.5

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: 10/16/2018

Vulnerability Publication Date: 5/2/2018

Reference Information

CVE: CVE-2018-10675, CVE-2018-14634, CVE-2018-5390, CVE-2018-5391

RHSA: 2018:2933