CVE-2024-43391
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 low privileged remote attacker can perform configuration changes of the firewall services, including packet filter, packet forwarding, network access control or NAT through the FW_PORTFORWARDING.SRC_IP environment variable which can lead to a DoS.
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 · moderate confidenceA low-privileged remote attacker can manipulate firewall service configurations (packet filter, forwarding, access control, NAT) through the FW_PORTFORWARDING.SRC_IP environment variable, allowing unauthorized modification of firewall rules leading to denial of service.
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< 8.9.3< 8.9.3< 8.9.3< 8.9.3< 8.9.3< 8.9.3< 8.9.3< 8.9.3CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/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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Identify the device modelDetermine if the target device is a Phoenixcontact Tc Mguard RS4000 or RS2000 variant (including 4g Vzw, 4g, 3g, ATT versions)Affected if The device is one of the listed affected models
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Check the installed firmware versionRetrieve the current firmware version from the device management interface or system settings and compare it to the affected range of versions < 8.9.3Affected if The firmware version is less than 8.9.3
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Verify firewall service accessibilityDetermine if the firewall service configuration interface is accessible to low-privileged or remote usersAffected if Low-privileged or remote users can access firewall configuration interfaces
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Inspect environment variable handlingCheck if the FW_PORTFORWARDING.SRC_IP environment variable can be manipulated by low-privileged users to modify firewall rulesAffected if The FW_PORTFORWARDING.SRC_IP environment variable can be controlled by low-privileged users to alter firewall configurations
The environment is affected if the device is a Phoenixcontact Tc Mguard RS2000 or RS4000 variant running firmware version less than 8.9.3 with accessible firewall configuration that allows manipulation via the FW_PORTFORWARDING.SRC_IP environment variable.
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 · scoped8.9.3
Restrict user privileges to prevent unauthorized firewall configuration changes; implement proper input validation on environment variables; apply vendor patches when available.
Firmware 8.9.3 or later for Tc Mguard RS2000/RS4000 series
- 1. Identify the exact Mguard model number (RS4000 or RS2000, including carrier variant such as VZW, ATT, or 3G/4G) from the device label or web interface
- 2. Backup the current device configuration through the web interface (System > Maintenance > Configuration > Backup) or CLI
- 3. Access the device's web interface and navigate to System > Maintenance > Firmware Update
- 4. Download the firmware version 8.9.3 or later from the official Allen-Bradley/Rockwell Automation support site or cert.vde.com referenced source
- 5. Upload the firmware file to the device and initiate the update process
- 6. Wait for the firmware upload and installation to complete - do not power off the device during this process
- 7. After reboot, verify the firmware version shows 8.9.3 or later in the web interface (Status > Overview)
- 8. Restore the backed-up configuration if needed through System > Maintenance > Configuration > Restore
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2024-43391 — 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-2024-43391 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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