SB2020073017 - Multiple vulnerabilities in GRUB2

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Main Vulnerability Database SB2020073017

SB2020073017 - Multiple vulnerabilities in GRUB2

Published: July 30, 2020

Security Bulletin ID SB2020073017
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Physical access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2020-15705)

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

CVSSv4: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local attacker to compromise the target system.

The vulnerability exists due to the affected software fails to validate kernel signature when booted directly without shim. An attacker with physical access can bypass secure boot.


2) Race condition (CVE-ID: CVE-2020-15706)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local attacker to execute arbitrary code and bypass secure boot restriction.

The vulnerability exists due to a race condition in the "grub_script_function_create()" function. An attacker with physical access can exploit the race and execute arbitrary code on the target system.


3) Integer overflow (CVE-ID: CVE-2020-15707)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local attacker to execute arbitrary code on the target system.

The vulnerability exists due to integer overflow in the "grub_cmd_initrd" and "grub_initrd_init" functions in the "efilinux" component. An attacker with physical access can pass specially crafted data to the application, trigger integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


Remediation

Install update from vendor's website.

References