Amazon Linux AMI : kernel (ALAS-2021-1516)

high Nessus Plugin ID 151521

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 4.14.238-125.421. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2021-1516 advisory.

2024-04-25: CVE-2021-46938 was added to this advisory.

A denial-of-service (DoS) flaw was identified in the Linux kernel due to an incorrect memory barrier in xt_replace_table in net/netfilter/x_tables.c in the netfilter subsystem. (CVE-2021-29650)

A flaw was found in kernel/bpf/verifier.c in BPF in the Linux kernel. An incorrect limit is enforced for pointer arithmetic operations which can be abused to perform out-of-bounds reads and writes in kernel memory, leading to local privilege escalation. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (CVE-2021-33200)

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

dm rq: fix double free of blk_mq_tag_set in dev remove after table load fails (CVE-2021-46938)

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.

See Also

https://alas.aws.amazon.com/ALAS-2021-1516.html

https://alas.aws.amazon.com/cve/html/CVE-2021-29650.html

https://alas.aws.amazon.com/cve/html/CVE-2021-33200.html

https://alas.aws.amazon.com/cve/html/CVE-2021-46938.html

https://alas.aws.amazon.com/faqs.html

Plugin Details

Severity: High

ID: 151521

File Name: ala_ALAS-2021-1516.nasl

Version: 1.4

Type: local

Agent: unix

Published: 7/13/2021

Updated: 12/11/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2021-33200

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

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:U/RL:O/RC:C

CVSS Score Source: CVE-2021-46938

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 Ease: No known exploits are available

Patch Publication Date: 7/8/2021

Vulnerability Publication Date: 3/30/2021

Reference Information

CVE: CVE-2021-29650, CVE-2021-33200, CVE-2021-46938

ALAS: 2021-1516