CVE-2020-28391
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 vulnerability has been identified in SCALANCE X-200 switch family (incl. SIPLUS NET variants) (All versions < V5.2.5), SCALANCE X-200IRT switch family (incl. SIPLUS NET variants) (All versions < V5.5.0), SCALANCE X-200RNA switch family (All versions < V3.2.7). Devices create a new unique key upon factory reset, except when used with C-PLUG. When used with C-PLUG the devices use the hardcoded private RSA-key shipped with the firmware-image. An attacker could leverage this situation to a man-in-the-middle situation and decrypt previously captured traffic.
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 SCALANCE X-200 series switches use a hardcoded RSA private key when operating with C-PLUG storage media instead of generating unique keys on factory reset. This key is shipped in the firmware image, meaning all affected devices share the same private key. An attacker with man-in-the-middle positioning can decrypt captured SSL/TLS traffic using this known private key.
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< 5.5.0< 5.5.0< 5.5.0< 5.5.0< 5.5.0< 5.5.0all versionsall 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
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:H/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 the SCALANCE device modelAccess the device web interface, CLI (typically via telnet/SSH), or SNMP to determine the exact model number (e.g., X200 4pirt, X202 2pirt, X307 3)Affected if The model is one of: X200 4pirt, X201 3pirt, X202 2irt, X202 2pirt, X202 2pirt Siplus Net, X204irt, X307 3, or X307 3ld
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Check the installed firmware versionUse the device CLI command 'show firmware' or 'show version', or check via the web interface under System > Firmware or Device InformationAffected if The firmware version is below 5.5.0 for X200/X201/X202/X204 models, or any version for X307 3 or X307 3ld models
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Verify if C-PLUG storage media is inserted and activeCheck the device web interface under C-PLUG/KEY-PLUG status page, or use CLI command 'show c-plug' or similar to determine if the C-PLUG is present and in useAffected if C-PLUG storage media is inserted and the device is using it for configuration storage
A user is affected if they have an affected SCALANCE X-200 series model with vulnerable firmware AND the C-PLUG storage media is actively in use, allowing potential decryption of SSL/TLS traffic by an attacker with man-in-the-middle positioning.
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 data5.5.0
Upgrade firmware to V5.2.5 (X-200), V5.5.0 (X-200IRT), or V3.2.7 (X-200RNA) respectively. If upgrading is not immediately feasible, avoid using C-PLUG for sensitive deployments and implement additional network segmentation.
- Consultation4.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-28391 — 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-2020-28391 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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