CVE-2023-4693

2023-10-0300:00:00

ubuntu.com

grub2

ntfs filesystem

out-of-bounds read

attacker

sensitive data

memory

efi variable

confidentiality

risk

secure boot

esm

i386 trusty

ga kernel

key revocation

cwe-125

unix

5.6 Medium

AI Score

Confidence

High

0.001 Low

EPSS

Percentile

32.0%

JSON

An out-of-bounds read flaw was found on grub2’s NTFS filesystem driver.
This issue may allow a physically present attacker to present a specially
crafted NTFS file system image to read arbitrary memory locations. A
successful attack allows sensitive data cached in memory or EFI variable
values to be leaked, presenting a high Confidentiality risk.

Notes

Author	Note
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-125

OSVersionArchitecturePackageVersionFilename
ubuntu18.04noarchgrub2-signed< anyUNKNOWN
ubuntu20.04noarchgrub2-signed< 1.187.6~20.04.1UNKNOWN
ubuntu22.04noarchgrub2-signed< 1.187.6UNKNOWN
ubuntu23.04noarchgrub2-signed< 1.193.2UNKNOWN
ubuntu23.10noarchgrub2-signed< 1.197UNKNOWN
ubuntu24.04noarchgrub2-signed< 1.199UNKNOWN
ubuntu16.04noarchgrub2-signed< anyUNKNOWN
ubuntu18.04noarchgrub2-unsigned< anyUNKNOWN
ubuntu20.04noarchgrub2-unsigned< 2.06-2ubuntu14.4UNKNOWN
ubuntu22.04noarchgrub2-unsigned< 2.06-2ubuntu14.4UNKNOWN

OS	Version	Architecture	Package	Version	Filename
ubuntu	18.04	noarch	grub2-signed	< any	UNKNOWN
ubuntu	20.04	noarch	grub2-signed	< 1.187.6~20.04.1	UNKNOWN
ubuntu	22.04	noarch	grub2-signed	< 1.187.6	UNKNOWN
ubuntu	23.04	noarch	grub2-signed	< 1.193.2	UNKNOWN
ubuntu	23.10	noarch	grub2-signed	< 1.197	UNKNOWN
ubuntu	24.04	noarch	grub2-signed	< 1.199	UNKNOWN
ubuntu	16.04	noarch	grub2-signed	< any	UNKNOWN
ubuntu	18.04	noarch	grub2-unsigned	< any	UNKNOWN
ubuntu	20.04	noarch	grub2-unsigned	< 2.06-2ubuntu14.4	UNKNOWN
ubuntu	22.04	noarch	grub2-unsigned	< 2.06-2ubuntu14.4	UNKNOWN