CVE-2021-34577
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 · uneditedIn the Kaden PICOFLUX AiR water meter an adversary can read the values through wireless M-Bus mode 5 with a hardcoded shared key while being adjacent to the device.
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 confidenceThe Kaden PICOFLUX AiR water meter uses wireless M-Bus mode 5 communication with a hardcoded shared cryptographic key. An attacker in proximity to the device can capture and decrypt wireless transmissions using this known key, allowing unauthorized reading of water consumption data.
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
- Adjacent
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/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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Identify Kaden PICOFLUX AiR meters in your inventoryReview asset inventories, IoT/device registries, or physically inspect installed water meters for 'Picoflux Air' or 'Kaden' branding on the device labelAffected if Any Kaden PICOFLUX AiR water meter is found in the environment
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Confirm wireless M-Bus is enabledAccess the meter configuration interface or documentation to verify if wireless M-Bus communication mode is activated on the deviceAffected if Wireless M-Bus transmission is enabled on the device
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Verify M-Bus mode settingCheck the device configuration or firmware settings to determine if M-Bus mode 5 (extended addressing with encryption) is in useAffected if The device is configured to use M-Bus mode 5 for wireless communication
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Check cryptographic key configurationExamine the meter's wireless configuration for the encryption key setting; compare against vendor documentation for default or hardcoded key valuesAffected if The device uses a pre-configured shared key rather than a unique, dynamically generated key
If Kaden PICOFLUX AiR meters with wireless M-Bus mode 5 enabled are present in the environment, the hardcoded key vulnerability applies and nearby attackers could decrypt consumption data.
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 dataReplace the hardcoded key with a dynamically generated or device-unique key, or implement proper key management. For deployed devices, apply vendor firmware updates if available and ensure physical security around meter installations.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34577 — 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-2021-34577 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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