Amazon Linux 2 : kernel (ALAS-2021-1719)

high Nessus Plugin ID 154914

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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 4.14.252-195.481. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1719 advisory.

A flaw was found in the Linux kernel. A corrupted timer tree caused the task wakeup to be missing in the timerqueue_add function in lib/timerqueue.c. This flaw allows a local attacker with special user privileges to cause a denial of service, slowing and eventually stopping the system while running OSP. The highest threat from this vulnerability is system availability. (CVE-2021-20317)

A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.
(CVE-2021-20321)

A flaw use-after-free in the Linux kernel USB High Speed Mobile Devices functionality was found in the way user detaches USB device. A local user could use this flaw to crash the system or escalate their privileges on the system. (CVE-2021-37159)

A flaw was found in the Linux kernel. A memory leak in the ccp-ops crypto driver can allow attackers to cause a denial of service. This vulnerability is similar with the older CVE-2019-18808. The highest threat from this vulnerability is to system availability. (CVE-2021-3744)

A memory leak flaw was found in the Linux kernel's ccp_run_aes_gcm_cmd() function that allows an attacker to cause a denial of service. The vulnerability is similar to the older CVE-2019-18808. The highest threat from this vulnerability is to system availability. (CVE-2021-3764)

A flaw was found in the Linux kernel. The cBPF JIT compiler may produce machine code with incorrect branches. This flaw allows an unprivileged user to craft anomalous machine code, where the control flow is hijacked to execute arbitrary kernel code. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. (CVE-2021-38300)

An out-of-bounds (OOB) memory write flaw was found in prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the bpf in the Linux kernel. In this flaw, the multiplication to calculate the size could lead to an integer overflow which could allow a local attacker, with a special user privilege, to gain access to out- of-bounds memory leading to a system crash or a leak of internal kernel information. (CVE-2021-41864)

In the Linux kernel, the following vulnerability has been resolved:

irqchip/gic-v3-its: Fix potential VPE leak on error (CVE-2021-47373)

In the Linux kernel, the following vulnerability has been resolved:

blktrace: Fix uaf in blk_trace access after removing by sysfs (CVE-2021-47375)

In the Linux kernel, the following vulnerability has been resolved:

tty: Fix out-of-bound vmalloc access in imageblit (CVE-2021-47383)

In the Linux kernel, the following vulnerability has been resolved:

cpufreq: schedutil: Use kobject release() method to free sugov_tunables (CVE-2021-47387)

In the Linux kernel, the following vulnerability has been resolved:

HID: betop: fix slab-out-of-bounds Write in betop_probe (CVE-2021-47404)

In the Linux kernel, the following vulnerability has been resolved:

nvmem: Fix shift-out-of-bound (UBSAN) with byte size cells (CVE-2021-47497)

Tenable has extracted the preceding description block directly from the tested product 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

Run 'yum update kernel' to update your system.

Plugin Details

Severity: High

ID: 154914

File Name: al2_ALAS-2021-1719.nasl

Version: 1.8

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 11/5/2021

Updated: 3/17/2025

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.6

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

CVSS Score Source: CVE-2021-38300

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

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:P/RL:O/RC:C

CVSS Score Source: CVE-2021-47404

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-debuginfo-common-aarch64, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:python-perf-debuginfo, p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-headers, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:kernel-livepatch-4.14.252-195.481, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:python-perf

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: 10/28/2021

Vulnerability Publication Date: 11/7/2019

Reference Information

CVE: CVE-2021-20317, CVE-2021-20321, CVE-2021-37159, CVE-2021-3744, CVE-2021-3764, CVE-2021-38300, CVE-2021-41864, CVE-2021-47373, CVE-2021-47375, CVE-2021-47383, CVE-2021-47387, CVE-2021-47404, CVE-2021-47497

ALAS: 2021-1719

Detections

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