Amazon Linux AMI : kernel (ALAS-2022-1563)

high Nessus Plugin ID 157410

Synopsis

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

Description

The version of kernel installed on the remote host is prior to 4.14.262-135.489. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2022-1563 advisory.

- Rogue backends can cause DoS of guests via high frequency events T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen offers the ability to run PV backends in regular unprivileged guests, typically referred to as driver domains.
Running PV backends in driver domains has one primary security advantage: if a driver domain gets compromised, it doesn't have the privileges to take over the system. However, a malicious driver domain could try to attack other guests via sending events at a high frequency leading to a Denial of Service in the guest due to trying to service interrupts for elongated amounts of time. There are three affected backends: * blkfront patch 1, CVE-2021-28711 * netfront patch 2, CVE-2021-28712 * hvc_xen (console) patch 3, CVE-2021-28713 (CVE-2021-28711, CVE-2021-28712, CVE-2021-28713)

- Guest can force Linux netback driver to hog large amounts of kernel memory T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. There are some measures taken for avoiding to pile up too much data, but those can be bypassed by the guest: There is a timeout how long the client side of an interface can stop consuming new packets before it is assumed to have stalled, but this timeout is rather long (60 seconds by default).
Using a UDP connection on a fast interface can easily accumulate gigabytes of data in that time.
(CVE-2021-28715) The timeout could even never trigger if the guest manages to have only one free slot in its RX queue ring page and the next package would require more than one free slot, which may be the case when using GSO, XDP, or software hashing. (CVE-2021-28714) (CVE-2021-28714, CVE-2021-28715)

Note that Nessus has not tested for this issue 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/ALAS-2022-1563.html

https://alas.aws.amazon.com/cve/html/CVE-2021-20322.html

https://alas.aws.amazon.com/cve/html/CVE-2021-28711.html

https://alas.aws.amazon.com/cve/html/CVE-2021-28712.html

https://alas.aws.amazon.com/cve/html/CVE-2021-28713.html

https://alas.aws.amazon.com/cve/html/CVE-2021-28714.html

https://alas.aws.amazon.com/cve/html/CVE-2021-28715.html

https://alas.aws.amazon.com/cve/html/CVE-2021-3772.html

https://alas.aws.amazon.com/cve/html/CVE-2021-4002.html

https://alas.aws.amazon.com/cve/html/CVE-2021-4155.html

https://alas.aws.amazon.com/cve/html/CVE-2022-0492.html

Plugin Details

Severity: High

ID: 157410

File Name: ala_ALAS-2022-1563.nasl

Version: 1.9

Type: local

Agent: unix

Published: 2/7/2022

Updated: 12/7/2023

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

Risk Information

VPR

Risk Factor: High

Score: 8.4

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.7

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

CVSS Score Source: CVE-2022-0492

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.2

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:F/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-debuginfo-common-i686, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, cpe:/o:amazon:linux

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2/4/2022

Vulnerability Publication Date: 1/11/2021

Exploitable With

Metasploit (Docker cgroups Container Escape)

Reference Information

CVE: CVE-2021-20322, CVE-2021-28711, CVE-2021-28712, CVE-2021-28713, CVE-2021-28714, CVE-2021-28715, CVE-2021-3772, CVE-2021-4002, CVE-2021-4155, CVE-2022-0492

ALAS: 2022-1563