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423 41w\/ac FirmwareOperating system · Furukawa

CVE-2021-37386

HIGH · 7.5 CVSS v3.1 Published 2023-07-17
Fix available
A fix is available. Upgrade to 1.2.0 / 1.4.0 or later.
See remediation →
79/100
Remediation priority · High
Remotely reachable

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
Furukawa Electric LatAm 423-41W/AC before v1.1.4 and LD421-21W before v1.3.3 were discovered to contain an HTML injection vulnerability via the serial number update function.

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

This is a stored HTML injection vulnerability in Furukawa Electric LatAm optical network equipment (models 423-41W/AC and LD421-21W). The serial number update function fails to properly sanitize or validate user-supplied input, allowing injection of arbitrary HTML tags. An attacker could exploit this to inject malicious scripts, perform phishing attacks, or manipulate page content viewed by other users.

MitigationUpdate firmware to v1.1.4 (for 423-41W/AC) or v1.3.3 (for LD421-21W) or later. Additionally, implement proper input validation and output encoding on the serial number update function to prevent HTML/script injection.

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
423 41w\/ac FirmwareOperating system
Affected:< 1.2.0
Ld421 21w FirmwareOperating system
Affected:< 1.5.0
Ld420 10r FirmwareOperating system
Affected:< 1.4.0
Ld421 21wv FirmwareOperating system
Affected:< 1.5.0

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
High
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/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
    Locate the physical device or check the web interface for the model number (423-41W/AC, LD421-21W, LD420-10R, or LD421-21WV). This is typically visible on the device label or in the device status page.
    Affected if The model is one of the four affected models listed in the CVE.
  2. Determine the firmware version
    Access the device web interface and navigate to the system information or about page to find the installed firmware version. Alternatively, check the administrative console for a firmware version display.
    Affected if Firmware version is below 1.2.0 for 423-41W/AC, below 1.5.0 for LD421-21W/LD421-21WV, or below 1.4.0 for LD420-10R.
  3. Verify web interface accessibility
    Confirm that the device web management interface is accessible on the network. Try accessing the device IP via HTTP/HTTPS in a browser.
    Affected if The web interface is exposed and reachable.
  4. Locate the serial number update function
    In the web interface, navigate to the device configuration or settings section where serial number updates can be performed. Look for fields labeled serial number, device serial, or similar.
    Affected if The serial number update functionality is present and accessible.

The device is affected if it is one of the four listed models running firmware versions below the specified thresholds and the serial number update function is accessible.

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 1.2.0 / 1.4.0 / 1.5.0 or later
Fixed in 1.2.01.4.01.5.0
Interim mitigation

Update firmware to v1.1.4 (for 423-41W/AC) or v1.3.3 (for LD421-21W) or later. Additionally, implement proper input validation and output encoding on the serial number update function to prevent HTML/script injection.

Recommended fix Moderate confidence

Firmware v1.2.0+ for 423-41W/AC; v1.5.0+ for LD421-21W/LD421-21WV; v1.4.0+ for LD420-10R

  1. 1. Identify the exact model and current firmware version of the Furukawa Electric device (423-41W/AC, LD421-21W, LD420-10R, or LD421-21WV)
  2. 2. Download the firmware update from the official Furukawa Electric Latin America support portal or authorized distributor
  3. 3. Back up the current device configuration according to the manufacturer's documentation
  4. 4. Connect to the device management interface via a trusted network connection
  5. 5. Upload and apply the firmware update: for 423-41W/AC upgrade to v1.2.0 or later, for LD421-21W upgrade to v1.5.0 or later, for LD420-10R upgrade to v1.4.0 or later, for LD421-21WV upgrade to v1.5.0 or later
  6. 6. Verify the firmware version has been successfully updated post-reboot
  7. 7. Confirm the serial number update function no longer accepts unsanitized input that could lead to HTML/XSS injection
  8. 8. Restore the device configuration from backup if needed
Caveat Firmware upgrades on network equipment may temporarily disrupt connectivity; ensure maintenance window and test in staging environment first

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

Fix this in 423 41w\/ac Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2021-37386 in production — separate from our analysis above.

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What this is

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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