Ubuntu 18.04 LTS : Linux kernel (HWE) vulnerabilities (USN-5071-2)

high Nessus Plugin ID 153445

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 18.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-5071-2 advisory.

USN-5071-1 fixed vulnerabilities in the Linux kernel for Ubuntu 20.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 20.04 LTS for Ubuntu 18.04 LTS.

Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel allowed a guest VM to disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a guest VM could use this to read or write portions of the host's physical memory.
(CVE-2021-3656)

Maxim Levitsky discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel did not properly prevent a guest VM from enabling AVIC in nested guest VMs. An attacker in a guest VM could use this to write to portions of the host's physical memory. (CVE-2021-3653)

It was discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel did not ensure enough processing time was given to perform cleanups of large SEV VMs. A local attacker could use this to cause a denial of service (soft lockup). (CVE-2020-36311)

It was discovered that the KVM hypervisor implementation in the Linux kernel did not properly perform reference counting in some situations, leading to a use-after-free vulnerability. An attacker who could start and control a VM could possibly use this to expose sensitive information or execute arbitrary code.
(CVE-2021-22543)

Murray McAllister discovered that the joystick device interface in the Linux kernel did not properly validate data passed via an ioctl(). A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code on systems with a joystick device registered. (CVE-2021-3612)

Tenable has extracted the preceding description block directly from the Ubuntu 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

Update the affected kernel package.

See Also

https://ubuntu.com/security/notices/USN-5071-2

Plugin Details

Severity: High

ID: 153445

File Name: ubuntu_USN-5071-2.nasl

Version: 1.11

Type: local

Agent: unix

Published: 9/16/2021

Updated: 8/28/2024

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

Risk Information

VPR

Risk Factor: High

Score: 7.3

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.6

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

CVSS Score Source: CVE-2021-3656

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-84-lowlatency, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-84-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-84-generic

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/16/2021

Vulnerability Publication Date: 4/7/2021

Reference Information

CVE: CVE-2020-36311, CVE-2021-22543, CVE-2021-3612, CVE-2021-3653, CVE-2021-3656

USN: 5071-2