Amazon Linux 2 : kernel (ALASKERNEL-5.15-2023-027)

high Nessus Plugin ID 182654

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 5.15.133-86.144. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.15-2023-027 advisory.

- A flaw was found in the Netfilter subsystem in the Linux kernel. The xt_u32 module did not validate the fields in the xt_u32 structure. This flaw allows a local privileged attacker to trigger an out-of-bounds read by setting the size fields with a value beyond the array boundaries, leading to a crash or information disclosure. (CVE-2023-39192)

- A flaw was found in the Netfilter subsystem in the Linux kernel. The sctp_mt_check did not validate the flag_count field. This flaw allows a local privileged (CAP_NET_ADMIN) attacker to trigger an out-of-bounds read, leading to a crash or information disclosure. (CVE-2023-39193)

- A flaw was found in the IPv4 Resource Reservation Protocol (RSVP) classifier in the Linux kernel. The xprt pointer may go beyond the linear part of the skb, leading to an out-of-bounds read in the `rsvp_classify` function. This issue may allow a local user to crash the system and cause a denial of service.
(CVE-2023-42755)

- An issue was discovered in drivers/net/ethernet/intel/igb/igb_main.c in the IGB driver in the Linux kernel before 6.5.3. A buffer size may not be adequate for frames larger than the MTU. (CVE-2023-45871)

- 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)

- In the Linux kernel, the following vulnerability has been resolved: netfilter: nftables: exthdr: fix 4-byte stack OOB write If priv->len is a multiple of 4, then dst[len / 4] can write past the destination array which leads to stack corruption. This construct is necessary to clean the remainder of the register in case ->len is NOT a multiple of the register size, so make it conditional just like nft_payload.c does.
The bug was added in 4.1 cycle and then copied/inherited when tcp/sctp and ip option support was added.
Bug reported by Zero Day Initiative project (ZDI-CAN-21950, ZDI-CAN-21951, ZDI-CAN-21961).
(CVE-2023-52628)

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-5.15-2023-027.html

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

https://alas.aws.amazon.com/cve/html/CVE-2023-45871.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-2023-52628.html

Plugin Details

Severity: High

ID: 182654

File Name: al2_ALASKERNEL-5_15-2023-027.nasl

Version: 1.8

Type: local

Agent: unix

Published: 10/6/2023

Updated: 4/26/2024

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-livepatch-5.15.133-86.144, 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: 9/6/2023

Reference Information

CVE: CVE-2023-39192, CVE-2023-39193, CVE-2023-42755, CVE-2023-45871, CVE-2023-4623, CVE-2023-4921, CVE-2023-52628