Ubuntu 16.04 LTS / 18.04 LTS / 20.04 : GRUB 2 vulnerabilities (USN-4432-1)

medium Nessus Plugin ID 139179

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Synopsis

The remote Ubuntu host is missing one or more security-related patches.

Description

Jesse Michael and Mickey Shkatov discovered that the configuration parser in GRUB2 did not properly exit when errors were discovered, resulting in heap-based buffer overflows. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2020-10713) Chris Coulson discovered that the GRUB2 function handling code did not properly handle a function being redefined, leading to a use-after-free vulnerability. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2020-15706) Chris Coulson discovered that multiple integer overflows existed in GRUB2 when handling certain filesystems or font files, leading to heap-based buffer overflows. A local attacker could use these to execute arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2020-14309, CVE-2020-14310, CVE-2020-14311) It was discovered that the memory allocator for GRUB2 did not validate allocation size, resulting in multiple integer overflows and heap-based buffer overflows when handling certain filesystems, PNG images or disk metadata. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2020-14308) Mathieu Trudel-Lapierre discovered that in certain situations, GRUB2 failed to validate kernel signatures. A local attacker could use this to bypass Secure Boot restrictions.
(CVE-2020-15705) Colin Watson and Chris Coulson discovered that an integer overflow existed in GRUB2 when handling the initrd command, leading to a heap-based buffer overflow. A local attacker could use this to execute arbitrary code and bypass UEFI Secure Boot restrictions. (CVE-2020-15707).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Update the affected packages.

See Also

https://usn.ubuntu.com/4432-1/

Plugin Details

Severity: Medium

ID: 139179

File Name: ubuntu_USN-4432-1.nasl

Version: 1.6

Type: local

Agent: unix

Published: 7/30/2020

Updated: 9/24/2020

Dependencies: ssh_get_info.nasl

Risk Information

CVSS Score Source: CVE-2020-14309

VPR

Risk Factor: Critical

Score: 10

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

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3

Risk Factor: Medium

Base Score: 6.7

Temporal Score: 5.8

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

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

Vulnerability Information

CPE: cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:*:*:*:*, cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:*:*:*:*, cpe:2.3:o:canonical:ubuntu_linux:18.04:-:lts:*:*:*:*:*, cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:*:*:*:*, p-cpe:2.3:a:canonical:ubuntu_linux:grub-efi-amd64-bin:*:*:*:*:*:*:*, p-cpe:2.3:a:canonical:ubuntu_linux:grub-efi-amd64-signed:*:*:*:*:*:*:*, p-cpe:2.3:a:canonical:ubuntu_linux:grub-efi-arm-bin:*:*:*:*:*:*:*, p-cpe:2.3:a:canonical:ubuntu_linux:grub-efi-arm64-bin:*:*:*:*:*:*:*, p-cpe:2.3:a:canonical:ubuntu_linux:grub-efi-arm64-signed:*:*:*:*:*:*:*, p-cpe:2.3:a:canonical:ubuntu_linux:grub-efi-ia32-bin:*:*:*:*:*:*:*

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

Exploit Ease: No known exploits are available

Patch Publication Date: 7/29/2020

Vulnerability Publication Date: 7/29/2020

Reference Information

CVE: CVE-2020-15705, CVE-2020-15706, CVE-2020-15707, CVE-2020-14308, CVE-2020-10713, CVE-2020-14309, CVE-2020-14310, CVE-2020-14311

USN: 4432-1

IAVA: 2020-A-0349