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Tofino Xenon Security Appliance FirmwareOperating system · Belden

CVE-2017-11401

CRITICAL · 9.8 CVSS v3.0 Published 2017-11-20
Fix available
A fix is available. Upgrade to after 3.1.0 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
An issue has been discovered on the Belden Hirschmann Tofino Xenon Security Appliance before 03.2.00. Improper handling of the mbap.length field of ModBus packets in the ModBus DPI filter allows an attacker to send malformed/crafted packets to a protected asset, bypassing function code filtering.

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 Tofino Xenon Security Appliance's ModBus DPI filter improperly handles the mbap.length field in ModBus packets. By crafting packets with manipulated length values, an attacker can bypass function code filtering and send malicious ModBus commands to protected industrial devices.

MitigationUpgrade Belden Hirschmann Tofino Xenon Security Appliance to firmware version 03.2.00 or later. Additionally, implement network segmentation to restrict direct access to ModBus devices from untrusted networks.

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
Tofino Xenon Security Appliance FirmwareOperating system
Affected:<= 3.1.0

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:3.0/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 Tofino Xenon Security Appliance in the network
    Locate the Belden Tofino Xenon Security Appliance by reviewing network topology diagrams, asset inventories, or by identifying the device's IP address or MAC OUI (Organization Unique Identifier) belonging to Belden/Hirschmann
    Affected if The device is a Belden Tofino Xenon Security Appliance
  2. Check the installed firmware version
    Access the appliance web interface, CLI console, or management software and navigate to the firmware or system information section to retrieve the current firmware version number
    Affected if The firmware version is 3.1.0 or lower
  3. Verify ModBus DPI filter is configured
    Access the appliance configuration interface and examine the ModBus deep packet inspection settings to confirm whether the ModBus DPI filter is enabled for any industrial protocol protection policy
    Affected if The ModBus DPI filter is enabled and protecting ModBus traffic
  4. Confirm ModBus traffic is being processed
    Review the appliance traffic logs, inspection statistics, or monitoring dashboards to verify that the Tofino appliance is actively processing ModBus protocol traffic
    Affected if The appliance is actively inspecting or filtering ModBus traffic

A user is affected if they have a Tofino Xenon Security Appliance running firmware version 3.1.0 or lower with the ModBus DPI filter enabled and processing ModBus traffic.

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 a release after 3.1.0
Interim mitigation

Upgrade Belden Hirschmann Tofino Xenon Security Appliance to firmware version 03.2.00 or later. Additionally, implement network segmentation to restrict direct access to ModBus devices from untrusted networks.

Recommended fix High confidence

Tofino Xenon Security Appliance Firmware version 03.2.00

  1. 1. Back up the current Tofino Xenon configuration and verify it can be restored if needed
  2. 2. Download the Tofino Xenon Firmware version 03.2.00 from the Belden/Hirschmann support portal
  3. 3. Review the firmware release notes for any specific upgrade prerequisites or注意事项
  4. 4. Apply the firmware upgrade to the Tofino Xenon Security Appliance following the vendor's documented upgrade procedure
  5. 5. After upgrade, verify the ModBus DPI filter is functioning correctly by testing with crafted packets that would have previously bypassed filtering
  6. 6. Confirm the mbap.length field is now properly validated in the ModBus DPI filter
Caveat As this is a security appliance firmware upgrade, test in a staging environment before production deployment to ensure compatibility with existing network configurations and monitored assets

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

Fix this in Tofino Xenon Security Appliance Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,330
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,728.

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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-2017-11401 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