Fl Nat 2008 FirmwareOperating system · Phoenixcontact

CVE-2025-41751

HIGH · 7.1 CVSS v3.1 Published 2025-12-09
Fix available
A fix is available. Upgrade to 3.50 or later.
See remediation →
78/100
Remediation priority · High
Remotely reachable No privileges

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 XSS vulnerability in pxc_portCntr.php can be used by an unauthenticated remote attacker to trick an authenticated user to click on the link provided by the attacker in order to change parameters available via web based management (WBM). The vulnerability does not provide access to system-level resources such as operating system internals or privileged functions. Access is limited to device configuration parameters that are available in the context of the web application. The session cookie is secured by the httpOnly Flag. Therefore an attacker is not able to take over the session of an authenticated user.

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 reflected XSS vulnerability in pxc_portCntr.php allows an unauthenticated remote attacker to craft malicious URLs that, when clicked by an authenticated user, can manipulate device configuration parameters accessible through the web-based management (WBM) interface. The httpOnly flag on session cookies prevents session hijacking, limiting impact to configuration parameter changes within the application's context.

MitigationImplement input validation and proper output encoding in pxc_portCntr.php to sanitize all user-supplied data before rendering it in the web interface. Consider adding CSRF tokens for configuration change requests to prevent authenticated users from inadvertently making unwanted changes via malicious links.

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
Fl Nat 2008 FirmwareOperating system
Affected:< 3.50
Fl Nat 2208 FirmwareOperating system
Affected:< 3.50
Fl Nat 2304 2gc 2sfp FirmwareOperating system
Affected:< 3.50
Fl Switch 2005 FirmwareOperating system
Affected:< 3.50
Fl Switch 2008 FirmwareOperating system
Affected:< 3.50
Fl Switch 2008f FirmwareOperating system
Affected:< 3.50
Fl Switch 2016 FirmwareOperating system
Affected:< 3.50
Fl Switch 2105 FirmwareOperating system
Affected:< 3.50

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
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

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 Phoenix Contact device model
    Access the web-based management (WBM) interface or check the device label/sticker to identify the exact model (e.g., FL NAT 2008, FL SWITCH 2008)
    Affected if The device model matches any of the affected products: FL NAT 2008, FL NAT 2208, FL NAT 2304 2gc 2sfp, FL SWITCH 2005, FL SWITCH 2008, FL SWITCH 2008f, FL SWITCH 2016, or FL SWITCH 2105
  2. Determine the firmware version
    Log into the WBM interface and navigate to System > Firmware or Status > Device Information to view the installed firmware version
    Affected if The firmware version is lower than 3.50 (e.g., 3.40, 3.30, etc.)
  3. Verify WBM web interface is accessible
    Attempt to access the device's web interface via HTTP/HTTPS on the expected management IP address
    Affected if The WBM interface is accessible and responds to requests
  4. Check if pxc_portCntr.php is present
    Access the URL path /pxc_portCntr.php through the web interface (e.g., http://<device-ip>/pxc_portCntr.php)
    Affected if The pxc_portCntr.php script returns a valid HTTP response rather than a 404 error, indicating the vulnerable script exists on the device
  5. Confirm user authentication is in use
    Check if the WBM interface requires login credentials and if session cookies are set for authenticated users
    Affected if The device has active user accounts configured and the WBM interface uses session-based authentication

The environment is affected if the device is one of the listed Phoenix Contact models running firmware version lower than 3.50 with the WBM interface accessible and the pxc_portCntr.php script present.

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 3.50 or later
Fixed in 3.50
Interim mitigation

Implement input validation and proper output encoding in pxc_portCntr.php to sanitize all user-supplied data before rendering it in the web interface. Consider adding CSRF tokens for configuration change requests to prevent authenticated users from inadvertently making unwanted changes via malicious links.

Recommended fix High confidence

Firmware version 3.50 or later for FL Nat 2008, FL Nat 2208, FL Nat 2304 2gc 2sfp, FL Switch 2005, FL Switch 2008, FL Switch 2008f, FL Switch 2016, FL Switch 2105

  1. 1. Access the web-based management (WBM) interface of the affected Phoenix Contact FL NAT or FL Switch device
  2. 2. Navigate to the firmware update section in the device management settings
  3. 3. Download the firmware version 3.50 or later from the official Phoenix Contact support website (https://www.phoenixcontact.com)
  4. 4. Upload and apply the new firmware to the device
  5. 5. After the firmware update completes, verify the device is functioning normally and the WBM interface is accessible
  6. 6. Confirm the XSS vulnerability in pxc_portCntr.php is resolved by attempting to inject test payloads (or verify via vulnerability scan)

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

Fix this in Fl Nat 2008 Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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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-2025-41751 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