CVE-2025-41749
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 · uneditedAn XSS vulnerability in port_util.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 · moderate confidenceAn XSS vulnerability in port_util.php allows an unauthenticated remote attacker to craft malicious links 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 the attacker's impact to modifying application-level configuration settings only.
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< 3.50< 3.50< 3.50< 3.50< 3.50< 3.50< 3.50< 3.50CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify the FL Switch modelAccess the device WBM interface or use SNMP/sysinfo to determine the exact model number (e.g., FL Switch 2008f, FL Switch 2016, FL Switch 2105, FL Switch 2108, FL Switch 2116, FL Switch 2204 2tc 2sfx, FL Switch 2205, or FL Switch 2206 2fx).Affected if The model is not one of the eight listed affected models - if your model is not in this list, you are not affected by this CVE.
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Check the installed firmware versionIn the WBM interface, navigate to System > Firmware Info or use the device's web interface to locate the firmware version. Compare it against the affected version threshold of 3.50.Affected if The firmware version is 3.50 or higher - versions 3.50 and later are not affected. If your version is below 3.50, proceed to the next check.
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Verify Web Based Management interface is accessibleConfirm that the WBM HTTP/HTTPS interface is enabled and reachable on the device. Check network accessibility and whether the web service is running.Affected if WBM is disabled or not accessible - the attack requires the WBM interface to be reachable. If WBM is accessible and firmware is below 3.50, the device may be affected.
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Confirm authenticated user sessions are possibleVerify that user authentication is configured for WBM access (local users, RADIUS, or TACACS+). The attack requires an authenticated user to click a crafted malicious link.Affected if WBM is configured with authentication and users can log in - the XSS payload requires a logged-in session to modify configuration parameters.
Your environment is affected if you have a Phoenix Contact FL Switch model from the affected list, running firmware version below 3.50, with the WBM interface accessible and user authentication enabled.
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 · scoped3.50
Implement proper input validation and output encoding in port_util.php to neutralize XSS vectors, and consider adding CSRF tokens for configuration change requests to prevent forced parameter modifications.
Firmware version 3.50
- 1. Backup the current device configuration through the web-based management (WBM) interface or via SNMP
- 2. Ensure stable power supply to the device during the firmware upgrade process
- 3. Download the firmware version 3.50 or later from the vendor's official support site (www.flnetworks.com or through certvde.com referenced channels)
- 4. Access the FL Switch web-based management interface using an authenticated session
- 5. Navigate to the System > Software or Firmware Update section
- 6. Upload and apply the firmware version 3.50 file
- 7. Wait for the device to complete the upgrade and reboot automatically
- 8. After reboot, verify the new firmware version is 3.50 or later in the WBM System Information page
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-41749 — 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-2025-41749 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
- No weaponised exploit code, or anything meant to cause harm
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