CVE-2021-20986
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 Denial of Service vulnerability was found in Hilscher PROFINET IO Device V3 in versions prior to V3.14.0.7. This may lead to unexpected loss of cyclic communication or interruption of acyclic communication.
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 confidenceA Denial of Service vulnerability exists in Hilscher PROFINET IO Device V3 versions prior to V3.14.0.7. When exploited, it causes unexpected loss of cyclic communication (real-time periodic data exchange) or interruption of acyclic communication (non-periodic configuration and diagnostics). The vulnerability allows an attacker to disrupt normal PROFINET IO Device operations without necessarily requiring authentication.
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>= 3.0, < 3.14.0.7<= 2.0.0<= 2.0.0<= 2.0.0<= 4.2.0<= 4.2.0<= 3.2.3<= 3.2.3CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 PROFINET IO Device firmware versionAccess the device management interface or use the manufacturer's diagnostic tool to retrieve the Hilscher PROFINET IO Device firmware version. For Hilscher devices, this is typically available via the netX configuration tool or web interface under firmware information.Affected if The firmware version is 3.0 or higher but lower than 3.14.0.7
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Identify Pepperl Fuchs device firmware versionCheck the firmware version of the Pepperl Fuchs device (Pgv100, Pgv150i, Pxv100, Pcv80, or Pcv100) through the device's web interface, configuration software, or PROFINET management system.Affected if The firmware version is 2.0.0 or lower for Pgv models, 4.2.0 or lower for Pxv models, or 3.2.3 or lower for Pcv models
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Verify PROFINET IO Device communication statusMonitor the PROFINET IO Device for unexpected loss of cyclic communication (real-time periodic data exchange) or interruption of acyclic communication (non-periodic configuration and diagnostics) using a PROFINET network analyzer or the device's diagnostic logs.Affected if Cyclic communication stops or acyclic communication is interrupted without other explainable causes
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Confirm PROFINET IO Device feature is activeVerify that the PROFINET IO Device functionality is enabled and running on the affected Hilscher or Pepperl Fuchs hardware. Check the device configuration for active PROFINET IO Device stack or firmware module.Affected if PROFINET IO Device is enabled and actively handling communication
Your environment is affected if you are running a Hilscher PROFINET IO Device firmware version between 3.0 and 3.14.0.6, or a Pepperl Fuchs device firmware at or below the affected versions listed, with PROFINET IO Device communication enabled.
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 data3.14.0.7
Upgrade Hilscher PROFINET IO Device V3 to version V3.14.0.7 or later. Prior to upgrading, establish a maintenance window and backup current configuration to ensure minimal operational disruption during the update process.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-20986 — 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-2021-20986 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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