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Ubuntu 18.04 LTS / 20.04 LTS : Linux kernel vulnerabilities (USN-4917-1)

high Nessus Plugin ID 148690

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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-4917-1 advisory.

 It was discovered that the overlayfs implementation in the Linux kernel did not properly validate the application of file system capabilities with respect to user namespaces. A local attacker could use this to gain elevated privileges. (CVE-2021-3493)

 Vincent Dehors discovered that the shiftfs file system in the Ubuntu Linux kernel did not properly handle faults in copy_from_user() when passing through ioctls to an underlying file system. A local attacker could use this to cause a denial of service (memory exhaustion) or execute arbitrary code. (CVE-2021-3492)

 Piotr Krysiuk discovered that the BPF JIT compiler for x86 in the Linux kernel did not properly validate computation of branch displacements in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2021-29154)

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-4917-1

Plugin Details

Severity: High

ID: 148690

File Name: ubuntu_USN-4917-1.nasl

Version: 1.12

Type: local

Agent: unix

Published: 4/16/2021

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: Critical

Score: 9.7

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 6.3

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

CVSS Score Source: CVE-2021-3493

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.5

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:H/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.3.0-1042-gke, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1034-raspi, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.3.0-1039-raspi2, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1045-aws, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.10.0-1022-oem, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.8.0-50-generic, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-72-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1014-gkeop, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-72-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1043-oracle, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.8.0-50-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.8.0-50-generic-64k, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1038-kvm, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.3.0-73-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1046-azure, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.8.0-50-lowlatency, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-72-lowlatency, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.3.0-73-lowlatency, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1042-gcp

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: 4/15/2021

Vulnerability Publication Date: 4/8/2021

CISA Known Exploited Vulnerability Due Dates: 11/10/2022

Exploitable With

CANVAS (CANVAS)

Core Impact

Metasploit (2021 Ubuntu Overlayfs LPE)

Reference Information

CVE: CVE-2021-29154, CVE-2021-3492, CVE-2021-3493

USN: 4917-1