Grub2Application · Gnu

CVE-2022-28734

HIGH · 7.0 CVSS v3.1 Published 2023-07-20
Fix available
A fix is available. Upgrade to 2.06-3 or later.
See remediation →
79/100
Remediation priority · High
Remotely reachable No privileges 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
Out-of-bounds write when handling split HTTP headers; When handling split HTTP headers, GRUB2 HTTP code accidentally moves its internal data buffer point by one position. This can lead to a out-of-bound write further when parsing the HTTP request, writing a NULL byte past the buffer. It's conceivable that an attacker controlled set of packets can lead to corruption of the GRUB2's internal memory metadata.

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

GRUB2's HTTP handling code has an off-by-one error when parsing split HTTP headers. The internal data buffer pointer is incorrectly advanced by one position, causing an out-of-bounds write of a NULL byte past the end of the buffer. This memory corruption could be exploited via attacker-controlled HTTP packets to compromise GRUB2's internal memory metadata.

MitigationUpdate GRUB2 to the patched version provided by your distribution or vendor. For systems with Secure Boot enabled, ensure the updated GRUB2 is properly re-signed and verify the boot chain integrity after patching.

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:>= 2.00, < 2.06-3
Active Iq Unified ManagerApplication
Affected:all versions

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
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/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 package version
    Run 'grub2-install --version' or 'rpm -q grub2' (RHEL/CentOS) or 'dpkg -l grub-pc' (Debian/Ubuntu) to determine the installed GRUB2 version
    Affected if The installed version is >= 2.00 and < 2.06-3 (for Gnu Grub2)
  2. Verify if GRUB2 supports HTTP boot
    Check if the grub package includes HTTP modules by listing /usr/lib/grub/*/http* or examining the boot configuration files in /boot/grub2/ or /boot/efi/EFI/*/grub.cfg for 'http' or 'network' boot entries
    Affected if HTTP modules exist and network boot configurations reference HTTP sources
  3. Identify network boot configurations
    Inspect bootloader configuration files (grub.cfg, grubenv) and check for HTTP boot entries, PXE configuration files, or boot parameters that include http:// URLs
    Affected if HTTP or network boot paths are configured in the bootloader
  4. Check NetApp Active IQ Unified Manager installation
    If the product is present, note that all versions are affected regardless of configuration
    Affected if NetApp Active IQ Unified Manager is installed on the system

A system is affected if it runs Gnu Grub2 version 2.00 through 2.06-2 with HTTP/network boot enabled, or if NetApp Active IQ Unified Manager is installed.

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 2.06-3 or later
Fixed in 2.06-3
Interim mitigation

Update GRUB2 to the patched version provided by your distribution or vendor. For systems with Secure Boot enabled, ensure the updated GRUB2 is properly re-signed and verify the boot chain integrity after patching.

Recommended fix High confidence

GRUB2 version 2.06-3 or later

  1. Check current GRUB2 version using: grub2 --version or grub-install --version
  2. Upgrade GRUB2 to version 2.06-3 or later from your Linux distribution's package manager or upstream source
  3. If using Secure Boot, rebuild GRUB2 images and re-sign them with appropriate keys
  4. Verify the upgrade was successful by checking the new version
  5. For Active IQ Unified Manager: Contact NetApp support for specific patch availability as all versions are affected
Caveat Ensure Secure Boot signatures are updated after upgrading GRUB2; test thoroughly in non-production environment first

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

Fix this in Grub2 Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,280
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2022-28734 in production — separate from our analysis above.

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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