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Grub2Application · Gnu

CVE-2025-0689

HIGH · 7.8 CVSS v3.1 Published 2025-03-03
Fix available
A fix is available. Upgrade to after 2.12 or later.
See remediation →
81/100
Remediation priority · High
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
When reading data from disk, the grub's UDF filesystem module utilizes the user controlled data length metadata to allocate its internal buffers. In certain scenarios, while iterating through disk sectors, it assumes the read size from the disk is always smaller than the allocated buffer size which is not guaranteed. A crafted filesystem image may lead to a heap-based buffer overflow resulting in critical data to be corrupted, resulting in the risk of arbitrary code execution by-passing secure boot protections.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

GRUB's UDF filesystem module uses user-controlled length metadata from the filesystem image to allocate internal buffers. During disk sector iteration, the code assumes the read size is always smaller than the allocated buffer without validating this assumption. A specially crafted UDF filesystem image can cause a heap-based buffer overflow by providing metadata that results in a smaller buffer than the actual read size, potentially allowing arbitrary code execution and bypassing Secure Boot protections.

MitigationApply the official GRUB security patch when available. In the interim, avoid mounting untrusted UDF filesystem images and ensure Secure Boot only loads trusted, signed bootloader images. Consider verifying UDF filesystem integrity before mounting in GRUB environments.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Grub2Application
Affected:<= 2.12

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check GRUB2 version
    Run 'grub-install --version' or 'dpkg -l | grep grub' (Debian/Ubuntu), 'rpm -qa | grep grub' (RHEL/Fedora), or check /boot/grub/i386-pc or x86_64-efi directory for version file
    Affected if Installed version is 2.12 or lower
  2. Identify UDF filesystem module
    Look for 'udf' module file in GRUB modules directory (typically /boot/grub/i386-pc/ or /boot/grub/x86_64-efi/); list with 'ls -la /boot/grub/*/udf*.mod'
    Affected if UDF module file exists in GRUB modules directory
  3. Verify UDF module is loaded or available
    Check GRUB configuration (typically /boot/grub/grub.cfg or /etc/grub.d/) for 'insmod udf' or 'module /udf.mod' statements, or examine GRUB menu entries for UDF-related commands
    Affected if GRUB configuration loads or references the UDF module
  4. Check if system can mount UDF images
    Review GRUB configuration for 'mount' commands or UDF filesystem access patterns; check if any boot entries or rescue media reference UDF-mounted volumes
    Affected if GRUB environment includes configuration to mount or access UDF filesystems
  5. Determine Secure Boot status
    Run 'mokutil --sb-state' (Linux) or check UEFI firmware settings for 'Secure Boot' status; on Windows use 'msinfo32' and look for 'Secure Boot State'
    Affected if Secure Boot is DISABLED (vulnerability can be exploited without this protection)

System is affected if running GRUB2 version 2.12 or lower with the UDF module loaded/enabled and Secure Boot is disabled or not enforcing bootloader integrity.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 2.12
Interim mitigation

Apply the official GRUB security patch when available. In the interim, avoid mounting untrusted UDF filesystem images and ensure Secure Boot only loads trusted, signed bootloader images. Consider verifying UDF filesystem integrity before mounting in GRUB environments.

Recommended fix Moderate confidence

Grub2 version greater than 2.12 (consult your distribution's security advisory for the exact fixed version)

  1. 1. Identify the current Grub2 version installed on the system using: rpm -q grub2-common or dpkg -l | grep grub2
  2. 2. Check for available security updates for Grub2 in your distribution's package repository
  3. 3. Apply the distribution-specific security patch: for RHEL/Fedora use 'dnf update grub2' or 'yum update grub2', for Debian/Ubuntu use 'apt update && apt install grub2'
  4. 4. If using UEFI with Secure Boot, ensure the updated Grub binaries are properly signed with a valid signature
  5. 5. After updating, regenerate Grub configuration files if needed using 'grub2-mkconfig -o /boot/grub2/grub.cfg' (or the appropriate path for your system)
  6. 6. Reboot the system to load the updated Grub version
Caveat When updating Grub2, ensure any custom configuration changes are preserved; updating Grub may require re-signing binaries for Secure Boot environments

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Grub2 Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA8.0 h
44.0 hours of engineering $7,720
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-0689 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data