Improper Signature VerificationWeakness · CWE-347

CVE-2024-47943

CRITICAL · 9.8 CVSS v3.1 Published 2024-10-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
The firmware upgrade function in the admin web interface of the Rittal IoT Interface & CMC III Processing Unit devices checks if the patch files are signed before executing the containing run.sh script. The signing process is kind of an HMAC with a long string as key which is hard-coded in the firmware and is freely available for download. This allows crafting malicious "signed" .patch files in order to compromise the device and execute arbitrary code.

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

The firmware upgrade function in Rittal IoT Interface & CMC III Processing Unit devices performs signature verification on .patch files before executing the contained run.sh script. However, the HMAC signing key is hard-coded in the firmware and is publicly available in the downloadable firmware image, allowing attackers to craft maliciously 'signed' patch files and achieve arbitrary code execution on affected devices.

MitigationRemediate by updating to a firmware version that implements proper cryptographic code signing with a secure key management infrastructure, or implement network-level controls to restrict access to the admin web interface until a patch is available.

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
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 device model
    Log into the device web interface or check the physical device label for the model number. Look for 'Rittal IoT Interface' or 'CMC III Processing Unit' in the device identification section.
    Affected if The device is a Rittal IoT Interface or CMC III Processing Unit
  2. Determine the firmware version
    In the device web interface, navigate to System > Firmware or Status > Information to find the installed firmware version number.
    Affected if The firmware version is unknown or prior to the patched version
  3. Check if the admin web interface is network-accessible
    Attempt to access the device web management interface via its IP address on ports 80 or 443 from an external network location.
    Affected if The admin web interface is reachable from untrusted networks
  4. Verify if remote firmware upgrade is enabled
    In the web interface, go to Administration > Firmware Upgrade or Settings > Update and check if the upgrade function is enabled and accessible.
    Affected if The firmware upgrade feature is enabled and accessible to attackers
  5. Inspect firmware upgrade configuration
    Check the firmware upgrade settings page for any indication that .patch file uploads are accepted and whether signature verification is actually being performed.
    Affected if The device accepts .patch files for upgrades without additional authentication beyond admin login

You are affected if you have a Rittal IoT Interface or CMC III Processing Unit device with the firmware upgrade feature accessible, as the hardcoded HMAC key allows attackers to bypass signature verification on malicious patch files.

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

Remediate by updating to a firmware version that implements proper cryptographic code signing with a secure key management infrastructure, or implement network-level controls to restrict access to the admin web interface until a patch is available.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation40.0 h
  • Testing16.0 h
  • Review / QA8.0 h
72.0 hours of engineering $12,640
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $20,224.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-47943 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-47943 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