| Name | CVE-2021-20233 |
| Description | 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | DSA-4867-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| grub2 (PTS) | jessie, jessie (lts) | 2.02~beta2-22+deb8u2 | vulnerable |
| stretch (lts), stretch | 2.02~beta3-5+deb9u3 | vulnerable |
| buster (security), buster, buster (lts) | 2.06-3~deb10u4 | fixed |
| bullseye (security), bullseye | 2.06-3~deb11u6 | fixed |
| bookworm (security), bookworm | 2.06-13+deb12u1 | fixed |
| sid, trixie | 2.12-5 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| grub2 | source | buster | 2.02+dfsg1-20+deb10u4 | | DSA-4867-1 | |
| grub2 | source | (unstable) | 2.04-16 | | | |
Notes
[stretch] - grub2 <ignored> (No SecureBoot support in stretch)
[jessie] - grub2 <ignored> (No SecureBoot support in jessie)