CVE-2021-20987
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 and memory corruption vulnerability was found in Hilscher EtherNet/IP Core V2 prior to V2.13.0.21that may lead to code injection through network or make devices crash without recovery.
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 confidenceMemory corruption vulnerability in Hilscher EtherNet/IP Core V2 stack allows remote attackers to inject arbitrary code via specially crafted network packets or cause persistent device crashes without recovery.
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>= 2.0, < 2.13.0.21<= 1.2.1<= 1.10.0<= 1.10.0<= 1.10.0<= 1.10.0<= 1.10.0<= 1.10.0CVSS 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
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 Hilscher EtherNet/IP stack usageDetermine if the device uses Hilscher EtherNet/IP Core V2 stack by checking product documentation, firmware metadata, or device web interface for Hilscher-specific componentsAffected if Device explicitly uses Hilscher EtherNet/IP Core V2 stack from any of the affected product lines
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Check Hilscher Ethernet/IP Adapter firmware versionAccess the device management interface or use SNMP/sysinfo to retrieve the firmware version stringAffected if Firmware version is >= 2.0 and < 2.13.0.21
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Check Pepperl Fuchs WCS firmware versionAccess the WCS device via its web interface or management console and retrieve the firmware versionAffected if Firmware version is <= 1.2.1
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Check Pepperl Fuchs PXV/PXV100i/PXV100 firmware versionAccess the PXV, PXV100i, or PXV100 device via its web interface or management console and retrieve the firmware versionAffected if Firmware version is <= 1.10.0
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Check Pepperl Fuchs PCV series firmware versionAccess the PCV50, PCV80, or PCV100 device via its web interface or management console and retrieve the firmware versionAffected if Firmware version is <= 1.10.0 (for PCV50, PCV80, PCV100 models)
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Verify EtherNet/IP protocol is enabledCheck device network configuration settings to confirm EtherNet/IP adapter or scanner functionality is activeAffected if EtherNet/IP protocol stack is enabled and accessible on the network
Environment is affected if any device runs Hilscher EtherNet/IP Core V2 with firmware version below the patched release (2.13.0.21 for Hilscher adapters, or <=1.2.1/<=1.10.0 for Pepperl Fuchs variants) and has EtherNet/IP 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 data2.13.0.21
Update EtherNet/IP Core to version V2.13.0.21 or later; isolate affected devices behind network segmentation until patched.
- Consultation4.0 h
- Implementation6.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,312.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20987 — 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-2021-20987 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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