Out-of-bounds Write Affecting grub2-efi-x64 package, versions <1:2.06-2.amzn2.0.1


Severity

Recommended
medium

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.04% (6th percentile)

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  • Snyk IDSNYK-AMZN2-GRUB2EFIX64-1702266
  • published27 Sept 2021
  • disclosed3 Mar 2021

Introduced: 3 Mar 2021

CVE-2021-20233  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2 grub2-efi-x64 to version 1:2.06-2.amzn2.0.1 or higher.
This issue was patched in ALAS2-2021-1684.

NVD Description

Note: Versions mentioned in the description apply only to the upstream grub2-efi-x64 package and not the grub2-efi-x64 package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2 relevant fixed versions and status.

A flaw was found in grub2 in versions prior to 2.06. Setparam_prefix() in the menu rendering code performs a length calculation on the assumption that expressing a quoted single quote will require 3 characters, while it actually requires 4 characters which allows an attacker to corrupt memory by one byte for each quote in the input. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

CVSS Scores

version 3.1