CVE-2021-22740
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 · uneditedInformation Exposure vulnerability exists in homeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior which could cause information to be exposed when an unauthorized file is uploaded.
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 confidenceInformation Exposure vulnerability in homeLYnk (Wiser For KNX) and spaceLYnk V2.60 and prior where unauthorized file uploads can expose sensitive information. The vulnerability stems from insufficient access controls on the file upload functionality, allowing unauthenticated or unauthorized users to upload files that lead to information disclosure.
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<= 2.6.0<= 2.6.0CVSS 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
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/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 the device modelAccess the device web interface or check the device label/documentation to confirm whether it is a Schneider Electric spaceLYnk or homeLYnk controllerAffected if The device is a spaceLYnk or homeLYnk controller
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Check the firmware versionLog into the device web interface and navigate to Settings > About or check the firmware version via the device's administration panel. Compare the version number to the affected range <= 2.6.0Affected if The installed firmware version is 2.6.0 or lower
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Verify web interface accessibilityDetermine if the device web interface (HTTP/HTTPS) is accessible from network segments outside the trusted internal network. Check firewall rules and network exposureAffected if The web interface is accessible from untrusted networks without proper authentication barriers
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Inspect file upload functionalityLocate any file upload features in the web interface (typically under Settings, Configuration, or Application sections). Attempt to identify if the upload endpoint enforces authenticationAffected if File upload features are accessible without requiring valid authentication credentials
You are affected if you are running spaceLYnk or homeLYnk firmware version 2.6.0 or lower AND the device web interface or file upload functionality is accessible without proper authentication controls.
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 proper authentication and authorization checks on all file upload endpoints, restrict upload capabilities to authorized users only, and validate file types/contents before allowing storage.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-22740 — 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-2021-22740 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