Amazon Linux 2 : kernel (ALAS-2018-1038) (Spectre)

Medium Nessus Plugin ID 110455

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

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)

By mmap()ing a FUSE-backed file onto a process's memory containing
command line arguments (or environment strings), an attacker can cause
utilities from psutils or procps (such as ps, w) or any other program
which makes a read() call to the /proc/<pid>/cmdline (or
/proc/<pid>/environ) files to block indefinitely (denial of service)
or for some controlled time (as a synchronization primitive for other
attacks).(CVE-2018-1120)

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)

Solution

Run 'yum update kernel' and reboot the instance to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALAS-2018-1038.html

Plugin Details

Severity: Medium

ID: 110455

File Name: al2_ALAS-2018-1038.nasl

Version: 1.6

Type: local

Agent: unix

Published: 2018/06/12

Modified: 2018/09/19

Dependencies: 12634

Risk Information

Risk Factor: Medium

CVSS v2.0

Base Score: 4.9

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

CVSS v3.0

Base Score: 5.6

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, p-cpe:/a:amazon:linux:python-perf, p-cpe:/a:amazon:linux:python-perf-debuginfo, cpe:/o:amazon:linux:2

Patch Publication Date: 2018/09/15

Reference Information

CVE: CVE-2018-1120, CVE-2018-3639, CVE-2018-3693

ALAS: 2018-1038

IAVA: 2018-A-0174