CVE-2025-41756
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 · uneditedA low-privileged remote attacker can exploit the ubr-editfile method in wwwubr.cgi, an undocumented and unused API endpoint to write arbitrary files on the system.
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 confidenceA low-privileged remote attacker can exploit the ubr-editfile method in wwwubr.cgi, an undocumented and unused API endpoint, to write arbitrary files on the system. This allows an attacker with basic user access to perform file system writes, potentially leading to remote code execution or website defacement.
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< 6.0.1.0CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify firmware versionAccess the router admin interface or check the system information page to find the installed firmware version. This is typically found under System, Status, or About sections in the web UI.Affected if The installed version is lower than 6.0.1.0
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Locate wwwubr.cgiCheck if the wwwubr.cgi file exists on the web server by accessing it directly via HTTP/HTTPS (e.g., https://router-ip/wwwubr.cgi).Affected if The endpoint responds and is accessible (even if returning an error, the file exists)
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Verify ubr-editfile method existsExamine the wwwubr.cgi source code or send a request to the ubr-editfile method endpoint to confirm it is present in the binary/script.Affected if The ubr-editfile method is found within wwwubr.cgi
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Check for basic user accessVerify if any basic user account exists on the system with minimal privileges, as the vulnerability allows exploitation with low-privileged access.Affected if Basic user accounts are enabled or accessible on the router
You are affected if your Universal Bacnet Router firmware version is below 6.0.1.0 and the wwwubr.cgi endpoint with the ubr-editfile method is present and accessible to low-privileged users.
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 · scoped6.0.1.0
Remove or disable the unused ubr-editfile method in wwwubr.cgi, as it is undocumented and serves no documented purpose. Verify no legitimate functionality depends on this endpoint before removal.
Universal Bacnet Router Firmware version 6.0.1.0
- 1. Identify all instances of Universal Bacnet Router running firmware versions prior to 6.0.1.0
- 2. Review the MBS Solutions website (www.mbs-solutions.de) for the official firmware version 6.0.1.0 release notes and download
- 3. Download the firmware version 6.0.1.0 or later from the official vendor source
- 4. Follow the vendor's standard firmware upgrade procedure for the Universal Bacnet Router
- 5. After upgrading, verify that the wwwubr.cgi endpoint is no longer accessible or has been properly disabled
- 6. Confirm the firmware version has been successfully updated to 6.0.1.0 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-41756 — 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-2025-41756 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
- No spam, self-promotion, credentials, or personal data