CVE-2025-41695
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 dyn_conn.php can be used by an unauthenticated remote attacker to trick an authenticated user to send a manipulated POST request to the device 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 confidenceA reflected XSS vulnerability in dyn_conn.php allows an unauthenticated remote attacker to inject malicious script through a manipulated POST request. The attacker must social-engineer an authenticated user to trigger the attack, which can modify device configuration parameters accessible via web-based management. The httpOnly flag on session cookies prevents session hijacking, limiting impact to configuration changes within the WBM context.
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 device modelAccess the web-based management (WBM) interface or use SNMP/SSH to query the device model. Look for model identifiers: 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.Affected if The device is one of these specific Phoenix Contact FL NAT or FL Switch models.
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Check firmware versionIn the WBM interface, navigate to System > Firmware or System > Information to view the installed firmware version. Alternatively, use CLI command 'show firmware' or SNMP OID if available.Affected if The firmware version is lower than 3.50.
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Confirm WBM is enabledIn the WBM interface, verify that Web-based Management is enabled under Network > Interfaces or System > Services. Check that HTTP or HTTPS access to dyn_conn.php is permitted.Affected if Web-based management is enabled and accessible via HTTP/HTTPS.
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Locate dyn_conn.phpAttempt to access the file directly via browser: http://<device-ip>/dyn_conn.php or https://<device-ip>/dyn_conn.php. Check if the file exists and is reachable without authentication.Affected if The dyn_conn.php file is accessible via the web interface.
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Test for XSS vulnerabilitySend a crafted POST request to dyn_conn.php with a test XSS payload in a parameter (such as 'conn_name' or similar). Example: POST /dyn_conn.php with body parameter containing <script>alert('XSS')</script>. Observe if the payload is reflected unescaped in the response.Affected if The injected script payload is reflected in the response without HTML encoding or sanitization.
You are affected if you have a Phoenix Contact FL NAT or FL Switch device running firmware version低于3.50 with web-based management enabled and the dyn_conn.php file reflects unsanitized input.
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, sanitization, and output encoding in dyn_conn.php to neutralize XSS vectors. Additionally, add CSRF tokens to POST requests in WBM to prevent request forgery.
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. Identify the specific FL NAT or FL Switch model from the affected product list
- 2. Check the current firmware version of the device through the web-based management interface
- 3. Download the firmware version 3.50 or later from the official vendor website or support portal
- 4. Access the device's web-based management interface and navigate to the firmware upgrade section
- 5. Upload and apply the new firmware file following the vendor's documented upgrade procedure
- 6. After the device reboots, verify the firmware version has been updated to 3.50 or later
- 7. Confirm that the dyn_conn.php page now properly sanitizes user inputs to prevent XSS attacks
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,648.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-41695 — 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-2025-41695 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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- Version or environment caveats, and links to real fixes
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