CVE-2021-3697
grub2: Crafted JPEG image can lead to buffer underflow write in the heap
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · June 7, 2022
Updated · November 22, 2025
Description
A flaw was found in grub2 when handling JPEG images. This flaw allows an attacker to craft a malicious JPEG image, which leads to an underflow on a grub2's internal pointer, leading to a heap-based out-of-bounds write. Secure-boot mechanisms circumvention and arbitrary code execution may also be achievable.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 7.5CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
CWE-787 · Out-of-bounds Write