CVE-2024-45781
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 · uneditedA flaw was found in grub2. When reading a symbolic link's name from a UFS filesystem, grub2 fails to validate the string length taken as an input. The lack of validation may lead to a heap out-of-bounds write, causing data integrity issues and eventually allowing an attacker to circumvent 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 confidenceA heap out-of-bounds write vulnerability exists in grub2 when reading symbolic link names from UFS filesystems due to missing string length validation. This can cause data integrity issues and potentially allow attackers to bypass secure boot protections.
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
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/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 checksWork through these to decide whether this CVE applies to you.
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Check installed grub2 versionRun 'grub2-install --version' or 'rpm -q grub2' (RHEL) or 'dpkg -l grub2' (Debian) to find the installed version. Compare to the patched version in your distribution's security advisory.Affected if The installed version is older than the patched version for CVE-2024-45781 in your distribution's security database.
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Identify if UFS filesystem module is loaded in grubInspect your grub configuration file (usually /boot/grub2/grub.cfg or /boot/efi/EFI/*/grub.cfg) and look for lines loading the UFS module, such as 'insmod ufs' or 'module /boot/grub/i386-pc/ufs.mod'. Also check /etc/default/grub for custom modules.Affected if The UFS module (ufs.mod) is loaded in your grub configuration.
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Check for UFS filesystems mounted on the systemRun 'mount' or 'cat /proc/mounts' and look for any filesystems of type 'ufs'. Also check /etc/fstab for UFS entries.Affected if Any UFS filesystems are mounted or configured to be mounted on the system.
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Look for symbolic links on UFS filesystemsIf UFS filesystems exist, use 'find /path/to/ufs/mount -type l' to enumerate symbolic links. Symbolic links on UFS volumes are processed by grub2 during boot.Affected if Symbolic links exist on any UFS-mounted filesystem.
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Verify secure boot chain integrityCheck if secure boot is enabled in firmware and verify grub2 is signed: 'mokutil --sb-state' and 'sbverify --list /boot/efi/EFI/*/shimx64.efi' (or your bootloader path).Affected if Secure boot is enabled and grub2 is used as the bootloader, but the installed grub2 version is unpatched.
You are affected if grub2 with an unpatched version is installed, the UFS module is loaded in grub configuration, and UFS filesystems containing symbolic links exist on the system while using grub2 as the bootloader.
Generated from the published advisory. Verify against your own configuration.
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 dataApply the grub2 security patch that adds proper string length validation when reading symbolic link names from UFS filesystems. Verify secure boot integrity after patching.
- Consultation8.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $10,240.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-45781 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2024-45781 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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