CVE-2023-4692 [High] | Memory Corruption in Grub2

An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code execution and secure boot protection bypass may be achieved.

EDB-ID	Source	Kind	Published	Link
—	nvd_ref	exploit_tag		Exploit-DB ↗

EDB-ID

Source

Kind

Published

Link

—

nvd_ref

exploit_tag

Exploit-DB ↗

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-11-21	0.07%	0.00%	-0.07%
2	2025-11-18	0.00%	0.07%	+0.07%
3	2025-04-15	—	0.00%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-11-21

0.07%

0.00%

-0.07%

2025-11-18

0.00%

0.07%

+0.07%

2025-04-15

—

0.00%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:H) They need powerful rights—admin, root, or similar—before this pays off. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	0.8	6.0	[email protected]
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H): They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

0.8

6.0

[email protected]

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

OS Trackers for CVE-2023-4692

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2023-4692 not yet assigned priority: Debian including 1 source packages (grub2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2023-4692
`redhat`	low	—	https://access.redhat.com/security/cve/CVE-2023-4692
`suse`	high	CVE-2023-4692 severity important: SUSE including 401 source package names (1.2.3-2.2.63:grub2-2.06-150400.11.38.1, 1.2.3-2.2.63:grub2-i386-pc-2.06-150400.11.38.1, …), 1141 product×package rows across 215 product lines (Container rancher/elemental-teal-rt/5.4, Container rancher/elemental-teal/5.4, … (215 product lines)): Fixed 961, Known Affected 180.	https://www.suse.com/security/cve/CVE-2023-4692/
`ubuntu`	medium	CVE-2023-4692 medium priority: Ubuntu including 3 source packages (grub2, grub2-signed, grub2-unsigned), 36 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 17, not-affected 11, needs-triage 6, ignored 2.	https://ubuntu.com/security/CVE-2023-4692

Affected software / configurations for CVE-2023-4692

Vendor	Product	Version	Raw CPE
gnu	grub2	< 2.12	cpe:2.3:a:gnu:grub2::::::::
redhat	enterprise_linux	8.0	cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*
redhat	enterprise_linux	9.0	cpe:2.3:o:redhat:enterprise_linux:9.0:::::::*

References for CVE-2023-4692

URL	Tags
https://access.redhat.com/errata/RHSA-2024:2456
https://access.redhat.com/errata/RHSA-2024:3184
https://access.redhat.com/security/cve/CVE-2023-4692	Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2236613	Issue Tracking Third Party Advisory
https://dfir.ru/2023/10/03/cve-2023-4692-cve-2023-4693-vulnerabilities-in-the-grub-boot-manager/	Exploit Third Party Advisory
https://lists.gnu.org/archive/html/grub-devel/2023-10/msg00028.html	Mailing List
https://seclists.org/oss-sec/2023/q4/37	Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/10/msg00007.html
https://lists.fedoraproject.org/archives/list/[email protected]/message/FUU42E7CPYLATXOYVYNW6YTXXULAOV6L/
https://lists.fedoraproject.org/archives/list/[email protected]/message/OIRJ5UZRXX2KLR4IKBJEQUNGOCXMMDLY/
https://lists.fedoraproject.org/archives/list/[email protected]/message/PERFILCHFEUGG3OAMC6W55P6DDIBZK4Q/
https://security.gentoo.org/glsa/202311-14
https://security.netapp.com/advisory/ntap-20231208-0002/

URL

CVE-2023-4692 | Grub2: out-of-bounds write at fs/ntfs.c may lead to unsigned code execution

Public exploit references (Exploit-DB) for CVE-2023-4692

Exploit prediction scoring system (EPSS) score for CVE-2023-4692

Common vulnerability scoring system (CVSS) metrics for CVE-2023-4692

Weakness enumeration for CVE-2023-4692

OS Trackers for CVE-2023-4692

Affected software / configurations for CVE-2023-4692

References for CVE-2023-4692