Amazon Linux 2 : kernel (ALASKERNEL-5.10-2022-009)

high Nessus Plugin ID 160451

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 5.10.93-87.444. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.10-2022-009 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)

- In the Linux kernel through 5.15.2, hw_atl_utils_fw_rpc_wait in drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_utils.c allows an attacker (who can introduce a crafted device) to trigger an out-of-bounds write via a crafted length value. (CVE-2021-43975)

- A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11.
This occurs because of a race condition in tee_shm_get_from_id during an attempt to free a shared memory object. (CVE-2021-44733)

- pep_sock_accept in net/phonet/pep.c in the Linux kernel through 5.15.8 has a refcount leak.
(CVE-2021-45095)

- A heap-based buffer overflow flaw was found in the way the legacy_parse_param function in the Filesystem Context functionality of the Linux kernel verified the supplied parameters length. An unprivileged (in case of unprivileged user namespaces enabled, otherwise needs namespaced CAP_SYS_ADMIN privilege) local user able to open a filesystem that does not support the Filesystem Context API (and thus fallbacks to legacy handling) could use this flaw to escalate their privileges on the system. (CVE-2022-0185)

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-5.10-2022-009.html

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

https://alas.aws.amazon.com/cve/html/CVE-2021-4135.html

https://alas.aws.amazon.com/cve/html/CVE-2021-4155.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-2021-3923.html

https://alas.aws.amazon.com/cve/html/CVE-2021-43975.html

https://alas.aws.amazon.com/cve/html/CVE-2022-0185.html

Plugin Details

Severity: High

ID: 160451

File Name: al2_ALASKERNEL-5_10-2022-009.nasl

Version: 1.7

Type: local

Agent: unix

Published: 5/2/2022

Updated: 10/17/2023

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

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 6

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

CVSS Score Source: CVE-2022-0185

CVSS v3

Risk Factor: High

Base Score: 8.4

Temporal Score: 7.8

Vector: CVSS:3.0/AV:L/AC:L/PR:N/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: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-5.10.93-87.444, 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: 1/26/2022

Vulnerability Publication Date: 1/11/2021

Exploitable With

Core Impact

Reference Information

CVE: CVE-2021-28711, CVE-2021-28712, CVE-2021-28713, CVE-2021-28714, CVE-2021-28715, CVE-2021-3923, CVE-2021-4135, CVE-2021-4155, CVE-2021-43975, CVE-2022-0185