Ubuntu 18.04 LTS / 20.04 LTS : Linux kernel vulnerabilities (USN-4909-1)

high Nessus Plugin ID 148497

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-4909-1 advisory.

Loris Reiff discovered that the BPF implementation in the Linux kernel did not properly validate attributes in the getsockopt BPF hook. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-20194)

Olivier Benjamin, Norbert Manthey, Martin Mazein, and Jan H. Schnherr discovered that the Xen paravirtualization backend in the Linux kernel did not properly propagate errors to frontend drivers in some situations. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26930)

Jan Beulich discovered that multiple Xen backends in the Linux kernel did not properly handle certain error conditions under paravirtualization. An attacker in a guest VM could possibly use this to cause a denial of service (host domain crash). (CVE-2021-26931)

It was discovered that the network block device (nbd) driver in the Linux kernel contained a use-after- free vulnerability during device setup. A local attacker with access to the nbd device could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-3348)

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-4909-1

Plugin Details

Severity: High

ID: 148497

File Name: ubuntu_USN-4909-1.nasl

Version: 1.6

Type: local

Agent: unix

Published: 4/14/2021

Updated: 8/27/2024

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: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2021-26930

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: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1042-oracle, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1033-raspi, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-71-lowlatency, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1013-gkeop, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1041-gcp, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-71-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1037-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-71-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1043-aws, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1040-gke, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1044-azure

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

Exploit Ease: No known exploits are available

Patch Publication Date: 4/13/2021

Vulnerability Publication Date: 2/1/2021

Reference Information

CVE: CVE-2021-20194, CVE-2021-26930, CVE-2021-26931, CVE-2021-3348

USN: 4909-1