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Ubuntu 18.04 LTS / 20.04 LTS : GRUB 2 vulnerabilities (USN-4992-1)

high Nessus Plugin ID 150867

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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 packages installed that are affected by multiple vulnerabilities as referenced in the USN-4992-1 advisory.

 Mt Kukri discovered that the acpi command in GRUB 2 allowed privileged users to load crafted ACPI tables when secure boot is enabled. An attacker could use this to bypass UEFI Secure Boot restrictions.
 (CVE-2020-14372)

 Chris Coulson discovered that the rmmod command in GRUB 2 contained a use- after-free vulnerability. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions.
 (CVE-2020-25632)

 Chris Coulson discovered that a buffer overflow existed in the command line parser in GRUB 2. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions.
 (CVE-2020-27749)

 It was discovered that the cutmem command in GRUB 2 did not honor secure boot locking. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2020-27779)

 It was discovered that the option parser in GRUB 2 contained a heap overflow vulnerability. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions.
 (CVE-2021-20225)

 It was discovered that the menu rendering implementation in GRUB 2 did not properly calculate the amount of memory needed in some situations, leading to out-of-bounds writes. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2021-20233)

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 packages.

See Also

https://ubuntu.com/security/notices/USN-4992-1

Plugin Details

Severity: High

ID: 150867

File Name: ubuntu_USN-4992-1.nasl

Version: 1.5

Type: local

Agent: unix

Published: 6/18/2021

Updated: 8/27/2024

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-2021-20233

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.4

Vector: CVSS:3.0/AV:L/AC:L/PR:H/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:grub-efi-arm64-bin, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:grub-efi-amd64-signed, p-cpe:/a:canonical:ubuntu_linux:grub-efi-amd64, p-cpe:/a:canonical:ubuntu_linux:grub-efi-arm64-signed, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:grub-efi-amd64-bin, p-cpe:/a:canonical:ubuntu_linux:grub-efi-arm64

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: 6/18/2021

Vulnerability Publication Date: 7/30/2020

Reference Information

CVE: CVE-2020-14372, CVE-2020-25632, CVE-2020-27749, CVE-2020-27779, CVE-2021-20225, CVE-2021-20233

IAVA: 2020-A-0349

USN: 4992-1