CVE-2021-22764
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 CWE-287: Improper Authentication vulnerability exists in PowerLogic PM55xx, PowerLogic PM8ECC, PowerLogic EGX100 and PowerLogic EGX300 (see security notification for version infromation) that could cause loss of connectivity to the device via Modbus TCP protocol when an attacker sends a specially crafted HTTP request.
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 confidenceImproper authentication vulnerability in PowerLogic PM55xx, PM8ECC, EGX100, and EGX300 devices allows attackers to cause loss of Modbus TCP connectivity by sending specially crafted HTTP requests. This is a CWE-287 issue where authentication mechanisms can be bypassed or are insufficient, potentially allowing unauthorized actors to disrupt industrial communications.
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< 2.7.8< 10.7.3<= 2.5.4< 2.7.8CVSS 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
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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 device modelAccess the device web interface, check the device nameplate/documentation, or query the device via SNMP/sysinfo to confirm the exact model numberAffected if Device is a PowerLogic PM5560, PM5561, PM5562, PM5563, PM8ECC, EGX100, or EGX300
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Check firmware version on PM5560 or PM5563Navigate to the device web interface firmware or status page, or query the device via SNMP to retrieve the installed firmware versionAffected if Firmware version is less than 2.7.8 on a PM5560 or PM5563
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Check firmware version on PM5561Navigate to the device web interface firmware or status page, or query the device via SNMP to retrieve the installed firmware versionAffected if Firmware version is less than 10.7.3 on a PM5561
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Check firmware version on PM5562Navigate to the device web interface firmware or status page, or query the device via SNMP to retrieve the installed firmware versionAffected if Firmware version is 2.5.4 or lower on a PM5562
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Verify HTTP management interface is accessibleAttempt to access the device IP address via HTTP (port 80) from a management workstation or use a network port scanner to confirm the web service is running and reachableAffected if HTTP management interface is exposed and accessible on the network
A device is affected if it is a PM5560, PM5561, PM5562, PM5563, PM8ECC, EGX100, or EGX300 with a firmware version below the specified thresholds AND its HTTP management interface is network-accessible.
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 data2.7.810.7.3
Apply vendor-supplied firmware updates when available and implement network segmentation to isolate critical industrial devices from untrusted networks. Consider restricting HTTP access to the device management interfaces and monitoring for anomalous HTTP traffic patterns.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2021-22764 — 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-2021-22764 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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