CVE-2021-3695

CVE Details

Release Date:	2022-06-07
Impact:	Moderate	What is this?

Description

A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform some triage over the heap layout to achieve signifcant results, also the values written into the memory are repeated three times in a row making difficult to produce valid payloads. This flaw affects grub2 versions prior grub-2.12.

See more information about CVE-2021-3695 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	7.5
Vector String:	CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Version:	3.0
Attack Vector:	Local
Attack Complexity:	High
Privileges Required:	High
User Interaction:	None
Scope:	Changed
Confidentiality Impact:	High
Integrity Impact:	High
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 7 (grub2)	ELSA-2022-9469	2022-06-07
Oracle Linux version 7 (grub2)	ELSA-2023-12952	2023-10-27
Oracle Linux version 8 (grub2)	ELSA-2022-5095	2022-07-04
Oracle Linux version 8 (grub2)	ELSA-2022-9471	2022-06-07
Oracle Linux version 8 (grub2)	ELSA-2022-9595	2022-07-14
Oracle Linux version 9 (grub2)	ELSA-2022-5099	2022-06-30
Oracle Linux version 9 (grub2)	ELSA-2022-9596	2022-07-14