Amazon Linux 2 : kernel (ALASKERNEL-5.4-2022-013)

medium Nessus Plugin ID 160448

Synopsis

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

Description

The version of kernel installed on the remote host is prior to 5.4.50-25.83. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.4-2022-013 advisory.

- A logic bug flaw was found in Linux kernel before 5.8-rc1 in the implementation of SSBD. A bug in the logic handling allows an attacker with a local account to disable SSBD protection during a context switch when additional speculative execution mitigations are in place. This issue was introduced when the per task/process conditional STIPB switching was added on top of the existing SSBD switching. The highest threat from this vulnerability is to confidentiality. (CVE-2020-10766)

- A flaw was found in the Linux kernel before 5.8-rc1 in the implementation of the Enhanced IBPB (Indirect Branch Prediction Barrier). The IBPB mitigation will be disabled when STIBP is not available or when the Enhanced Indirect Branch Restricted Speculation (IBRS) is available. This flaw allows a local attacker to perform a Spectre V2 style attack when this configuration is active. The highest threat from this vulnerability is to confidentiality. (CVE-2020-10767)

- A flaw was found in the Linux Kernel before 5.8-rc1 in the prctl() function, where it can be used to enable indirect branch speculation after it has been disabled. This call incorrectly reports it as being 'force disabled' when it is not and opens the system to Spectre v2 attacks. The highest threat from this vulnerability is to confidentiality. (CVE-2020-10768)

- An issue was discovered in the Linux kernel through 5.6.11. btree_gc_coalesce in drivers/md/bcache/btree.c has a deadlock if a coalescing operation fails. (CVE-2020-12771)

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

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALASKERNEL-5.4-2022-013.html

https://alas.aws.amazon.com/cve/html/CVE-2020-10766.html

https://alas.aws.amazon.com/cve/html/CVE-2020-10767.html

https://alas.aws.amazon.com/cve/html/CVE-2020-10768.html

https://alas.aws.amazon.com/cve/html/CVE-2020-12771.html

Plugin Details

Severity: Medium

ID: 160448

File Name: al2_ALASKERNEL-5_4-2022-013.nasl

Version: 1.3

Type: local

Agent: unix

Published: 5/2/2022

Updated: 6/7/2022

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

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

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS Score Source: CVE-2020-10768

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

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

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

Vulnerability Information

CPE: cpe:2.3:o:amazon:linux:2:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-debuginfo-common-x86_64:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-devel:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-headers:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-tools:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-tools-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-tools-devel:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:perf:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:perf-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:python-perf:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:python-perf-debuginfo:*:*:*:*:*:*:*, p-cpe:2.3:a:amazon:linux:kernel-debuginfo-common-aarch64:*:*:*:*:*:*:*

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

Exploit Ease: No known exploits are available

Patch Publication Date: 1/20/2022

Vulnerability Publication Date: 5/9/2020

Reference Information

CVE: CVE-2020-12771, CVE-2020-10766, CVE-2020-10767, CVE-2020-10768