CVE-2023-35120
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 · uneditedPiiGAB M-Bus is vulnerable to cross-site request forgery. An attacker who wants to execute a certain command could send a phishing mail to the owner of the device and hope that the owner clicks on the link. If the owner of the device has a cookie stored that allows the owner to be logged in, then the device could execute the GET or POST link request.
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 confidencePiiGAB M-Bus lacks anti-CSRF protections, allowing authenticated users to be tricked into executing unintended commands via malicious links. An attacker sends a phishing email containing a crafted GET or POST request that exploits the user's active session cookie.
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 dataall versionsCVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/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 Piigab M-Bus 900s device on your networkLocate the device via network inventory, MAC vendor lookup (PiiGAB), or by accessing the web interface and checking the device model/firmware information pageAffected if The device model shows as Piigab M-Bus 900s with any firmware version
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Confirm all firmware versions are affectedCheck the installed firmware version in the device web UI under System Info, Status, or About pagesAffected if The device is a Piigab M-Bus 900s regardless of version - all versions are affected
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Inspect web forms for anti-CSRF token presenceLog into the device web interface, navigate to any configuration or state-changing form (such as settings, actions, or admin functions), view the page source or intercept the HTTP request to check if a unique token parameter is submitted with the formAffected if No anti-CSRF token or unique security token is present in state-changing form submissions
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Verify session cookie SameSite attributeWhile logged into the web interface, open browser developer tools, go to Application/Storage tab, find the session cookie, and inspect its attributes - or capture an HTTP response Set-Cookie headerAffected if The session cookie does not have the SameSite attribute set, or it is set to 'None' without Secure flag
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Check for Referer/Origin header validationSubmit a state-changing request (e.g., changing a setting) with a manipulated or missing Referer/Origin header using a tool like Burp Suite or curl to see if the request is acceptedAffected if The device accepts state-changing requests without proper Referer/Origin validation
If you have a Piigab M-Bus 900s device exposed on your network and its web interface lacks anti-CSRF tokens on forms, does not set SameSite on session cookies, and does not validate Referer/Origin headers, your environment is affected by CVE-2023-35120.
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.
From vendor dataImplement anti-CSRF tokens on all state-changing operations and set SameSite attribute on session cookies; add Referer/Origin header validation as additional defense.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,680.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-35120 — 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-2023-35120 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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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.
- 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