Amazon Linux 2 : kernel (ALASKERNEL-5.4-2023-053)

high Nessus Plugin ID 182660

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 5.4.257-170.359. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.4-2023-053 advisory.

- A flaw was found in the Linux kernel's IP framework for transforming packets (XFRM subsystem). This issue may allow a malicious user with CAP_NET_ADMIN privileges to directly dereference a NULL pointer in xfrm_update_ae_params(), leading to a possible kernel crash and denial of service. (CVE-2023-3772)

- An array indexing vulnerability was found in the netfilter subsystem of the Linux kernel. A missing macro could lead to a miscalculation of the `h->nets` array offset, providing attackers with the primitive to arbitrarily increment/decrement a memory buffer out-of-bound. This issue may allow a local user to crash the system or potentially escalate their privileges on the system. (CVE-2023-42753)

- A use-after-free vulnerability in the Linux kernel's af_unix component can be exploited to achieve local privilege escalation. The unix_stream_sendpage() function tries to add data to the last skb in the peer's recv queue without locking the queue. Thus there is a race where unix_stream_sendpage() could access an skb locklessly that is being released by garbage collection, resulting in use-after-free. We recommend upgrading past commit 790c2f9d15b594350ae9bca7b236f2b1859de02c. (CVE-2023-4622)

- A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation. If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free. We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f. (CVE-2023-4623)

- A use-after-free vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited to achieve local privilege escalation. When the plug qdisc is used as a class of the qfq qdisc, sending network packets triggers use-after-free in qfq_dequeue() due to the incorrect .peek handler of sch_plug and lack of error checking in agg_dequeue(). We recommend upgrading past commit 8fc134fee27f2263988ae38920bc03da416b03d8. (CVE-2023-4921)

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-5.4-2023-053.html

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

https://alas.aws.amazon.com/cve/html/CVE-2023-3772.html

https://alas.aws.amazon.com/cve/html/CVE-2023-39192.html

https://alas.aws.amazon.com/cve/html/CVE-2023-39193.html

https://alas.aws.amazon.com/cve/html/CVE-2023-39194.html

https://alas.aws.amazon.com/cve/html/CVE-2023-4622.html

https://alas.aws.amazon.com/cve/html/CVE-2023-4623.html

https://alas.aws.amazon.com/cve/html/CVE-2023-4921.html

https://alas.aws.amazon.com/cve/html/CVE-2023-42753.html

https://alas.aws.amazon.com/cve/html/CVE-2023-42755.html

https://alas.aws.amazon.com/cve/html/CVE-2023-45871.html

Plugin Details

Severity: High

ID: 182660

File Name: al2_ALASKERNEL-5_4-2023-053.nasl

Version: 1.6

Type: local

Agent: unix

Published: 10/6/2023

Updated: 1/5/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

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

CVSS Score Source: CVE-2023-4921

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:bpftool, p-cpe:/a:amazon:linux:bpftool-debuginfo, p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64, 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

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: 9/27/2023

Vulnerability Publication Date: 7/25/2023

Reference Information

CVE: CVE-2023-3772, CVE-2023-39192, CVE-2023-39193, CVE-2023-39194, CVE-2023-42753, CVE-2023-42755, CVE-2023-45871, CVE-2023-4622, CVE-2023-4623, CVE-2023-4921