CVE-2025-4382

Publication date 9 May 2025

Last updated 14 May 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

5.9 · Medium

Score breakdown

A flaw was found in systems utilizing LUKS-encrypted disks with GRUB configured for TPM-based auto-decryption. When GRUB is set to automatically decrypt disks using keys stored in the TPM, it reads the decryption key into system memory. If an attacker with physical access can corrupt the underlying filesystem superblock, GRUB will fail to locate a valid filesystem and enter rescue mode. At this point, the disk is already decrypted, and the decryption key remains loaded in system memory. This scenario may allow an attacker with physical access to access the unencrypted data without any further authentication, thereby compromising data confidentiality. Furthermore, the ability to force this state through filesystem corruption also presents a data integrity concern.

Read the notes from the security team

Status

Package Ubuntu Release Status
grub2 25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
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 Ignored update incompatible with kernel
grub2-signed 25.04 plucky
Needs evaluation
24.10 oracular
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty Ignored update incompatible with kernel
grub2-unsigned 25.04 plucky
Needs evaluation
24.10 oracular
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation

Notes

eslerm

the grub2 package does not affect Ubuntu's Secure Boot grub2-unsigned contains Secure Boot security fixes grub2 and grub2-unsigned should have same major version 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)

Severity score breakdown

Parameter Value
Base score 5.9 · Medium
Attack vector Physical
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality High
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N