Scientific Linux Security Update : kernel on SL6.x i386/x86_64 (Foreshadow)

High Nessus Plugin ID 111777

Synopsis

The remote Scientific Linux host is missing one or more security updates.

Description

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)

- 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)

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.

Solution

Update the affected packages.

See Also

http://www.nessus.org/u?d03c589b

Plugin Details

Severity: High

ID: 111777

File Name: sl_20180814_kernel_on_SL6_x.nasl

Version: 1.4

Type: local

Agent: unix

Published: 2018/08/16

Updated: 2019/07/11

Dependencies: 12634

Risk Information

Risk Factor: High

CVSS v2.0

Base Score: 7.2

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

CVSS v3.0

Base Score: 7.8

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

Vulnerability Information

CPE: x-cpe:/o:fermilab:scientific_linux

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

Patch Publication Date: 2018/08/14

Vulnerability Publication Date: 2017/10/16

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-2018-7566