Vulnerability identifier: #VU81627

Vulnerability risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2023-4692

CWE-ID: CWE-787

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
grub
Universal components / Libraries / Libraries used by multiple products

Vendor: GNU

Description

The vulnerability allows a local user to bypass secure boot protection.

The vulnerability exists due to a boundary error in NTFS driver implementation in grub-core/fs/ntfs.c when parsing the $ATTRIBUTE_LIST attribute for the $MFT file. A local user can pass a specially crafted image to the application, trigger an out-of-bounds write and bypass secure boot protection.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

grub: 1.99 - 2.06

---

External links
http://lists.gnu.org/archive/html/grub-devel/2023-10/msg00028.html

---

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.