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CVE-2023-4692

Publication date 3 October 2023

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.8 · High

Score breakdown

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.

From the Ubuntu Security Team

It was discovered that a specially crafted file system image could cause a heap-based out-of-bounds write. An attacker could potentially use this to perform arbitrary code execution bypass and bypass secure boot protections.

Read the notes from the security team

Status

Package Ubuntu Release Status
grub2 24.04 LTS noble
Not affected
23.10 mantic
Not affected
23.04 lunar
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
grub2-signed 24.04 LTS noble
Fixed 1.197
23.10 mantic
Fixed 1.197
23.04 lunar
Fixed 1.193.2
22.04 LTS jammy
Fixed 1.187.6
20.04 LTS focal
Fixed 1.187.6~20.04.1
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty Ignored
grub2-unsigned 24.04 LTS noble
Fixed 2.12~rc1-10ubuntu4
23.10 mantic
Fixed 2.12~rc1-10ubuntu4
23.04 lunar
Fixed 2.06-2ubuntu17.2
22.04 LTS jammy
Fixed 2.06-2ubuntu14.4
20.04 LTS focal
Fixed 2.06-2ubuntu14.4
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty Ignored

Notes

eslerm

grub2-unsigned contains Secure Boot security fixes the grub2 package unlikely affects Ubuntu's Secure Boot grub2 and grub2-unsigned should have same major version

eslerm

Ubuntu Secure Boot and ESM do not cover i386 trusty's GA kernel cannot handle new versions of grub Note that key revocation is required to protect against evil housekeeper attacks (such as BlackLotus)

eslerm

CWE-122

Severity score breakdown

Parameter Value
Base score 7.8 · High
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Related Ubuntu Security Notices (USN)

Other references