Synopsis
The remote Red Hat host is missing one or more security updates for kernel.
Description
The remote Redhat Enterprise Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2018:2785 advisory.
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)
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.
Bug Fix(es):
* On systems running Red Hat Enterprise Linux 7 with Red Hat OpenShift Container Platform 3.5, a node sometimes got into NodeNotReady state after a CPU softlockup. Consequently, the node was not available.
This update fixes an irq latency source in memory compaction. As a result, nodes no longer get into NodeNotReady state under the described circumstances. (BZ#1596281)
* Previously, the kernel source code was missing support to report the Speculative Store Bypass Disable (SSBD) vulnerability status on IBM Power Systems and the little-endian variants of IBM Power Systems. As a consequence, the /sys/devices/system/cpu/vulnerabilities/spec_store_bypass file incorrectly reported Not affected on both CPU architectures. This fix updates the kernel source code to properly report the SSBD status either as Vulnerable or Mitigation: Kernel entry/exit barrier (TYPE) where TYPE is one of eieio, hwsync, fallback, or unknown. (BZ#1612351)
* The hypervisors of Red Hat Enterprise Linux 7 virtual machines (VMs) in certain circumstances mishandled the microcode update in the kernel. As a consequence, the VMs sometimes became unresponsive when booting.
This update applies an upstream patch to avoid early microcode update when running under a hypervisor. As a result, kernel hangs no longer occur in the described scenario. (BZ#1618388)
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-2018:2785.
Plugin Details
File Name: redhat-RHSA-2018-2785.nasl
Agent: unix
Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Nessus
Risk Information
Vendor
Vendor Severity: Important
Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C
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:U/RL:O/RC:C
Vulnerability Information
CPE: p-cpe:/a:redhat:enterprise_linux:kernel-tools, p-cpe:/a:redhat:enterprise_linux:kernel, p-cpe:/a:redhat:enterprise_linux:kernel-headers, cpe:/o:redhat:rhel_eus:7.3, p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs-devel, 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:kernel-tools-libs, 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 Ease: No known exploits are available
Patch Publication Date: 9/25/2018
Vulnerability Publication Date: 5/2/2018