dbcve.org
Use After FreeWeakness · CWE-416

CVE-2025-0622

MEDIUM · 6.4 CVSS v3.1 Published 2025-02-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
66/100
Remediation priority · Elevated
Zero-click

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
A flaw was found in command/gpg. In some scenarios, hooks created by loaded modules are not removed when the related module is unloaded. This flaw allows an attacker to force grub2 to call the hooks once the module that registered it was unloaded, leading to a use-after-free vulnerability. If correctly exploited, this vulnerability may result in arbitrary code execution, eventually allowing the attacker to bypass 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 · moderate confidence

A use-after-free vulnerability exists in GRUB2's gpg command module where hooks registered by loaded modules are not properly cleaned up when the module is unloaded. An attacker can exploit this by forcing GRUB2 to call hooks from an already-unloaded module, leading to arbitrary code execution and potential secure boot bypass.

MitigationApply the vendor patch to GRUB2 and rebuild/re-sign the bootloader. For systems with secure boot enabled, ensure the new GRUB2 binary is properly signed and deployed. Consider disabling unused GRUB2 modules to reduce attack surface.

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

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
High
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/PR:H/UI:N/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. Locate the gpg module file
    Find grub.cfg and check the module directory (typically /boot/grub/i386-pc/ or /usr/lib/grub/i386-pc/ or similar path depending on OS). Search for a file named 'gpg.mod' or 'gpg.module'.
    Affected if The gpg.mod file exists in the GRUB2 module directory, meaning the vulnerable module is present in the installation.
  2. Check GRUB2 version against available patches
    Run 'grub2-mkversion' or check the installed GRUB2 package version via package manager (dpkg -l grub2-common, rpm -q grub2, etc.). Compare to any vendor-advisory version numbers if available.
    Affected if The installed version predates the vendor patch date or is older than the fixed version (if published by the distribution).
  3. Verify dynamic module loading is enabled
    Inspect /boot/grub/grub.cfg (or /etc/grub2.cfg) and look for 'insmod' directives, particularly any that load the gpg module or module loading configuration. Also check /etc/default/grub for GRUB_LOADABLE_MODULE variable settings.
    Affected if GRUB is configured to dynamically load modules (insmod commands present) or modules are stored in a loadable location.
  4. Identify module unload paths
    Review any custom GRUB scripts or configuration files in /etc/grub.d/ that may invoke module unloading or replacement. Check for scripts that might dynamically load then unload the gpg module during boot.
    Affected if Custom GRUB scripts or configurations that manipulate module loading/unloading exist and reference the gpg or cryptographic modules.
  5. Check for secure boot interactions
    If Secure Boot is enabled, verify the GRUB2 binary is signed. Use 'sbverify --list /boot/efi/EFI/*/grubx64.efi' or equivalent to check existing signatures. An attacker exploiting this flaw could potentially load an unsigned module if the signed boundary is bypassed.
    Affected if Secure Boot is enabled and the GRUB2 installation permits loading external modules (even if signed), which could be a vector for the bypass aspect of this vulnerability.

A system is affected if GRUB2 with the gpg module is installed and supports dynamic module loading, as the use-after-free can be triggered when hooks from the unloaded module are invoked.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patch to GRUB2 and rebuild/re-sign the bootloader. For systems with secure boot enabled, ensure the new GRUB2 binary is properly signed and deployed. Consider disabling unused GRUB2 modules to reduce attack surface.

Have this fixed 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
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-0622 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2025-0622 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data