Amazon Linux 2 : kernel (ALAS-2021-1685)

high Nessus Plugin ID 151793

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 4.14.238-182.421. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1685 advisory.

- Bluetooth LE and BR/EDR secure pairing in Bluetooth Core Specification 2.1 through 5.2 may permit a nearby man-in-the-middle attacker to identify the Passkey used during pairing (in the Passkey authentication procedure) by reflection of the public key and the authentication evidence of the initiating device, potentially permitting this attacker to complete authenticated pairing with the responding device using the correct Passkey for the pairing session. The attack methodology determines the Passkey value one bit at a time. (CVE-2020-26558)

- Improper access control in BlueZ may allow an authenticated user to potentially enable information disclosure via adjacent access. (CVE-2021-0129)

- An issue was discovered in the Linux kernel before 5.11.11. The netfilter subsystem allows attackers to cause a denial of service (panic) because net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h lack a full memory barrier upon the assignment of a new table value, aka CID-175e476b8cdf.
(CVE-2021-29650)

- net/bluetooth/hci_request.c in the Linux kernel through 5.12.2 has a race condition for removal of the HCI controller. (CVE-2021-32399)

- In the Linux kernel before 5.12.4, net/bluetooth/hci_event.c has a use-after-free when destroying an hci_chan, aka CID-5c4c8c954409. This leads to writing an arbitrary value. (CVE-2021-33034)

- In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db. (CVE-2021-33624)

- A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system. This flaw affects all the Linux kernel versions starting from 3.13. (CVE-2021-3564)

Note that Nessus has not tested for this issue 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/ALAS-2021-1685.html

https://access.redhat.com/security/cve/CVE-2020-26558

https://access.redhat.com/security/cve/CVE-2021-0129

https://access.redhat.com/security/cve/CVE-2021-29650

https://access.redhat.com/security/cve/CVE-2021-32399

https://access.redhat.com/security/cve/CVE-2021-33034

https://access.redhat.com/security/cve/CVE-2021-33624

https://access.redhat.com/security/cve/CVE-2021-3564

https://access.redhat.com/security/cve/CVE-2021-3573

Plugin Details

Severity: High

ID: 151793

File Name: al2_ALAS-2021-1685.nasl

Version: 1.4

Type: local

Agent: unix

Published: 7/16/2021

Updated: 5/9/2022

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

Risk Information

CVSS Score Source: CVE-2021-3573

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.1

Vector: AV:L/AC:M/Au:N/C:C/I:C/A:C

Temporal Vector: E:U/RL:OF/RC:C

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: E:U/RL:O/RC:C

Vulnerability Information

CPE: 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-4.14.238-182.421, 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 Ease: No known exploits are available

Patch Publication Date: 7/14/2021

Vulnerability Publication Date: 3/30/2021

Reference Information

CVE: CVE-2020-26558, CVE-2021-0129, CVE-2021-3564, CVE-2021-3573, CVE-2021-29650, CVE-2021-32399, CVE-2021-33034, CVE-2021-33624

ALAS: 2021-1685