CVE-2021-20233 is a memory corruption vulnerability in grub2 versions prior to 2.06, affecting products from Fedora, GNU, NetApp, and Red Hat. This flaw arises from an incorrect length calculation in the menu rendering code, allowing a one-byte memory corruption for each quote in the input. With a CVSS score of 8.2 (High), this vulnerability poses a significant threat to data confidentiality, integrity, and system availability, requiring high privileges for exploitation. There is currently no public exploit code available (Metasploit, Nuclei, ExploitDB), it is not listed in the KEV catalog, and community discussion and media coverage are minimal, suggesting limited active exploitation.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 2.06CPE matchmatch criteria | cpe:2.3:a:gnu:grub2:*:*:*:*:*:*:*:* | ||
7.0CPE matchmatch criteria | cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* | ||
8.0CPE matchmatch criteria | cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | ||
7.2CPE matchmatch criteria | cpe:2.3:o:redhat:enterprise_linux_server_aus:7.2:*:*:*:*:*:*:* | ||
7.3CPE matchmatch criteria | cpe:2.3:o:redhat:enterprise_linux_server_aus:7.3:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
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.
Mar 9, 2021grub2: Heap out-of-bounds write due to miscalculation of space required for quoting
Mar 2, 2021