ShimApplication · Redhat
CVE-2022-28737
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 · uneditedThere's a possible overflow in handle_image() when shim tries to load and execute crafted EFI executables; The handle_image() function takes into account the SizeOfRawData field from each section to be loaded. An attacker can leverage this to perform out-of-bound writes into memory. Arbitrary code execution is not discarded in such scenario.
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 buffer overflow vulnerability exists in the handle_image() function of a bootloader shim component. The function uses the SizeOfRawData field from EFI executable sections without proper validation, allowing an attacker to craft a malicious EFI executable that triggers out-of-bounds memory writes and potentially achieve arbitrary code execution during the boot process.
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
ShimApplication
< 15.6CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Locate the shim EFI binarySearch for shim*.efi files in /boot/efi/EFI/ or /efi/EFI/ directories, or use 'find /boot -name shim*.efi 2>/dev/null' to find the installed shim binaryAffected if No shim binary is found - the system may use a different bootloader or have shim installed elsewhere
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Determine the installed shim versionRun 'rpm -q shim-x64' (or 'rpm -qa | grep shim') on Red Hat-based systems, or use 'efitools' to read the shim version: 'objdump -p /path/to/shimx64.efi | grep -i version'Affected if The version number returned is less than 15.6 (e.g., 15.5, 15.4, etc.)
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Check if Secure Boot is enabledRun 'mokutil --sb-state' or check the UEFI firmware settings directly; the shim is only invoked during boot when Secure Boot is activeAffected if Secure Boot is enabled - the shim is actively used in the boot chain and the vulnerability is exploitable
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Verify the shim is used in the boot chainCheck /boot/efi/EFI/*/shim*.efi exists and is referenced by the bootloader configuration, or inspect 'efibootmgr -v' output for shim involvementAffected if The shim binary is present in the EFI system partition and is part of the secure boot chain
The system is affected if Red Hat Shim version 15.6 or higher is not installed AND Secure Boot is enabled, allowing the shim to be used during the boot process.
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.
dbcve · scoped15.6
Apply the vendor-provided patch to the shim component and ensure all affected systems receive the updated version. Verify the update through secure boot chain validation.
Shim 15.6
- Obtain Shim binary version 15.6 or later from the official Shim project or your Linux distribution's secure package repository
- Replace the existing Shim bootloader binary (shimx64.efi for x86-64, shimaa64.efi for ARM64, or shimia32.efi for 32-bit) with the updated version
- Ensure the new Shim binary is properly signed with a trusted UEFI signature (Shim requires Microsoft UEFI CA signing or a vendor-specific key)
- Verify the upgrade was successful by checking the Shim version in the bootloader or system information
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Shim
Scoped from the published advisory
- Consultation8.0 h
- Implementation4.0 h
- Testing16.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,856.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-28737 — 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-2022-28737 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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