CVE-2021-22749
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 CWE-200: Exposure of Sensitive Information to an Unauthorized Actor vulnerability exists in Modicon X80 BMXNOR0200H RTU SV1.70 IR22 and prior that could cause information leak concerning the current RTU configuration including communication parameters dedicated to telemetry, when a specially crafted HTTP request is sent to the web server of the module.
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 CWE-200 information disclosure vulnerability in the Modicon X80 BMXNOR0200H RTU web server allows unauthenticated attackers to craft HTTP requests that leak sensitive RTU configuration data including communication parameters for telemetry systems.
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= sv1.6= sv1.7CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
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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Confirm device modelIdentify the Modicon X80 BMXNOR0200H RTU device in your environment through device inventory, network scanning, or by accessing the device web interface and checking the model informationAffected if The device is not a Modicon X80 BMXNOR0200H RTU, then this CVE does not apply
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Check firmware versionAccess the device web interface or use SNMP/management interface to retrieve the firmware version. Look for version identifier 'sv1.6' or 'sv1.7'Affected if Firmware version is exactly sv1.6 or sv1.7, indicating the device is in the affected version range
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Verify web server is enabledConfirm that the embedded web server feature is enabled on the RTU device. This is typically accessible via HTTP on the device management interfaceAffected if The web server is enabled and reachable, making the information disclosure vulnerability accessible to unauthenticated attackers
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Test for configuration data leakSend a crafted HTTP request to the web server endpoint without authentication. If vulnerable, the response will include sensitive RTU configuration data such as communication parameters for telemetry systemsAffected if Unauthenticated HTTP requests return sensitive RTU configuration data including communication parameters, confirming active exploitation of the vulnerability
The device is affected if it is a Modicon X80 BMXNOR0200H RTU running firmware version sv1.6 or sv1.7, and the web server is enabled and accessible to unauthenticated network attackers.
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 dataApply the vendor patch (SV1.70 IR22 or later) and restrict web server access to authorized personnel via network segmentation or firewall rules.
- Consultation3.0 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-2021-22749 — 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-2021-22749 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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