Ubuntu 18.04 LTS / 20.04 LTS : Linux kernel vulnerabilities (USN-4679-1)

high Nessus Plugin ID 144750

Synopsis

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

Description

The remote Ubuntu 18.04 LTS / 20.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-4679-1 advisory.

It was discovered that the console keyboard driver in the Linux kernel contained a race condition. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-25656)

Minh Yuan discovered that the tty driver in the Linux kernel contained race conditions when handling fonts. A local attacker could possibly use this to expose sensitive information (kernel memory).
(CVE-2020-25668)

Kiyin () discovered that the perf subsystem in the Linux kernel did not properly deallocate memory in some situations. A privileged attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2020-25704)

Jinoh Kang discovered that the Xen event channel infrastructure in the Linux kernel contained a race condition. An attacker in guest could possibly use this to cause a denial of service (dom0 crash).
(CVE-2020-27675)

Daniel Axtens discovered that PowerPC RTAS implementation in the Linux kernel did not properly restrict memory accesses in some situations. A privileged local attacker could use this to arbitrarily modify kernel memory, potentially bypassing kernel lockdown restrictions. (CVE-2020-27777)

Minh Yuan discovered that the framebuffer console driver in the Linux kernel did not properly handle fonts in some conditions. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory). (CVE-2020-28974)

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-4679-1

Plugin Details

Severity: High

ID: 144750

File Name: ubuntu_USN-4679-1.nasl

Version: 1.9

Type: local

Agent: unix

Published: 1/6/2021

Updated: 8/29/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

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-2020-27777

CVSS v3

Risk Factor: High

Base Score: 7

Temporal Score: 6.3

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

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

CVSS Score Source: CVE-2020-25668

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-59-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-59-lowlatency, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1033-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1035-azure, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1033-gke, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1034-oracle, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-59-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1031-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1026-raspi

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 1/6/2021

Vulnerability Publication Date: 10/22/2020

Reference Information

CVE: CVE-2020-25656, CVE-2020-25668, CVE-2020-25704, CVE-2020-27675, CVE-2020-27777, CVE-2020-28974

USN: 4679-1