dbcve.org
Gecko BootloaderApplication · Silabs

CVE-2023-4041

CRITICAL · 9.8 CVSS v3.1 Published 2023-08-23
Fix available
A fix is available. Upgrade to 4.2.4 / 4.3.2 or later.
See remediation →
100/100
Remediation priority · Urgent
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
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'), Out-of-bounds Write, Download of Code Without Integrity Check vulnerability in Silicon Labs Gecko Bootloader on ARM (Firmware Update File Parser modules) allows Code Injection, Authentication Bypass.This issue affects "Standalone" and "Application" versions of Gecko Bootloader.

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

A buffer overflow vulnerability in the Firmware Update File Parser modules of Silicon Labs Gecko Bootloader on ARM allows out-of-bounds writes during firmware parsing, combined with a lack of integrity verification for downloaded code. This enables arbitrary code injection and authentication bypass in affected bootloader implementations.

MitigationUpdate the Gecko Bootloader to a patched version provided by Silicon Labs and re-flash all affected devices; implement cryptographic signature verification for firmware updates before deployment.

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
Gecko BootloaderApplication
Affected:< 4.2.4>= 4.3.0, < 4.3.2

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

CVSS:3.1/AV:N/AC:L/PR:N/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. Identify the installed Gecko Bootloader version
    Use Silicon Labs Simplicity Studio Device Debugger or slc-cli to query the bootloader version from the target device. Alternatively, check the bootloader binary or build artifacts for embedded version strings.
    Affected if The bootloader version is less than 4.2.4, or greater than or equal to 4.3.0 but less than 4.3.2.
  2. Confirm firmware update functionality is enabled
    Examine the bootloader configuration (bootloader-config.h or custom bootloader configuration) to verify that the Gecko Bootloader firmware update parsing module is included in the build. Check project settings for enabled bootloader components.
    Affected if The firmware update parser module is present and enabled in the bootloader build.
  3. Verify if integrity verification is disabled
    Review the bootloader configuration files for GBL_PARSE_ENABLE or similar flags related to firmware integrity. Check whether cryptographic signature verification (AUTHENTICATE_BL and GBL_AUTHENTICATE flags) is defined but not enforced or is absent.
    Affected if The bootloader lacks enforced cryptographic signature verification for firmware updates, or integrity verification is explicitly disabled in the configuration.
  4. Check for vulnerable parser module in build
    Inspect the compiled bootloader image or build output for the presence of gbl_parser.c, gbl_parser.o, or related firmware file parsing components. Confirm the parser module version through build metadata if available.
    Affected if The GBL parser module is included in the bootloader build without the corresponding security patches.

You are affected if your device runs a Gecko Bootloader version within the vulnerable ranges AND has firmware update parsing enabled with integrity verification disabled or missing.

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 4.2.4 / 4.3.2 or later
Fixed in 4.2.44.3.2
Interim mitigation

Update the Gecko Bootloader to a patched version provided by Silicon Labs and re-flash all affected devices; implement cryptographic signature verification for firmware updates before deployment.

Recommended fix Moderate confidence

Gecko Bootloader 4.2.4 or later; or Gecko Bootloader 4.3.2 or later

  1. Identify the current installed Gecko Bootloader version using Silicon Labs Simplicity Studio or the bootloader version command
  2. Download Gecko Bootloader version 4.2.4 or later (if using 4.2.x branch), or version 4.3.2 or later (if using 4.3.x branch) from Silicon Labs
  3. If using Simplicity Studio, use the Device Provisioner or Flash Programmer tool to update the bootloader
  4. Alternatively, if deploying via firmware update mechanism, package the new bootloader as a firmware update and deploy through the standard update process
  5. After upgrading, verify the bootloader version has been correctly updated
  6. Test that the device boots properly and firmware update functionality works with the new bootloader
Caveat Bootloader updates may require recalibration of device-specific settings; thoroughly test application compatibility with the new bootloader version before production deployment

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

Fix this in Gecko Bootloader Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA6.0 h
30.0 hours of engineering $5,120
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,192.

Scan for this in your stack

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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-2023-4041 in production — separate from our analysis above.

No notes yet

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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