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Ubuntu 20.04 LTS : Linux kernel vulnerabilities (USN-5070-1)

high Nessus Plugin ID 153174

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Synopsis

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

Description

The remote Ubuntu 20.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-5070-1 advisory.

 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 Linux kernel did not properly enforce certain types of entries in the Secure Boot Forbidden Signature Database (aka dbx) protection mechanism. An attacker could use this to bypass UEFI Secure Boot restrictions. (CVE-2020-26541)

 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)

 Norbert Slusarek discovered that the CAN broadcast manger (bcm) protocol implementation in the Linux kernel did not properly initialize memory in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2021-34693)

 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)

 It was discovered that the KVM hypervisor implementation in the Linux kernel did not properly compute the access permissions for shadow pages in some situations. A local attacker could use this to cause a denial of service. (CVE-2021-38198)

 It was discovered that the perf subsystem in the Linux kernel for the PowerPC architecture contained a null pointer dereference in some situations. An attacker could use this to cause a denial of service (system crash). (CVE-2021-38200)

 Ben Greear discovered that the mac80211 subsystem in the Linux kernel contained a null pointer dereference in some situations. A physically proximate attacker could possibly use this to cause a denial of service (system crash). (CVE-2021-38206)

 It was discovered that the Xilinx LL TEMAC device driver in the Linux kernel did not properly calculate the number of buffers to be used in certain situations. A remote attacker could use this to cause a denial of service (system crash). (CVE-2021-38207)

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-5070-1

Plugin Details

Severity: High

ID: 153174

File Name: ubuntu_USN-5070-1.nasl

Version: 1.8

Type: local

Agent: unix

Published: 9/9/2021

Updated: 9/19/2024

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

CVSS v4

Risk Factor: High

Base Score: 8.7

Threat Score: 7.2

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

CVSS Score Source: CVE-2021-22543

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.11.0-1017-oracle, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.11.0-1017-aws, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.11.0-34-generic-lpae, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.11.0-34-generic, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.11.0-34-generic-64k, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.11.0-1015-azure, p-cpe:/a:canonical:ubuntu_linux:linux-image-5.11.0-34-lowlatency

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: 9/8/2021

Vulnerability Publication Date: 10/2/2020

Reference Information

CVE: CVE-2020-26541, CVE-2021-22543, CVE-2021-34693, CVE-2021-3612, CVE-2021-3653, CVE-2021-3656, CVE-2021-38198, CVE-2021-38200, CVE-2021-38206, CVE-2021-38207

USN: 5070-1