CVE-2023-22357
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 · uneditedActive debug code exists in OMRON CP1L-EL20DR-D all versions, which may lead to a command that is not specified in FINS protocol being executed without authentication. A remote unauthenticated attacker may read/write in arbitrary area of the device memory, which may lead to overwriting the firmware, causing a denial-of-service (DoS) condition, and/or arbitrary code execution.
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 confidenceActive debug code present in OMRON CP1L-EL20DR-D PLC firmware allows unauthenticated remote attackers to execute commands outside the FINS protocol specification. Attackers can read/write arbitrary memory regions, enabling firmware overwriting, denial-of-service conditions, and arbitrary code execution.
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 dataall 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
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 the PLC modelLocate the PLC hardware unit nameplate or query the device via FINS protocol (command 0x0501) to read the model identification. Look for model number CP1L-EL20DR-D.Affected if The device model is CP1L-EL20DR-D, as all firmware versions of this model contain the debug code.
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Confirm firmware versionQuery the PLC firmware version using FINS command 0x0501 or via Cx-Programmer software under Device Properties. Note the version string returned.Affected if Any firmware version on CP1L-EL20DR-D is affected since the advisory states all versions contain the vulnerability.
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Check network exposure of the PLCReview network configuration and firewall rules to determine if the PLC Ethernet port is accessible from unauthorized network segments or external IP addresses. Use port scanning (e.g., nmap) to verify open ports 9600/UDP (FINS) and any unexpected open ports.Affected if The PLC is reachable from untrusted networks on its Ethernet interfaces, enabling unauthenticated remote attackers to reach the debug code.
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Detect unexpected open debug portsPerform a full port scan of the PLC IP address. Look for any open ports beyond the standard FINS port 9600/UDP, such as Telnet (23), debug interfaces, or undocumented services.Affected if Any non-standard open port is detected on the PLC, as the vulnerability stems from hidden debug services in the firmware.
If the device is an OMRON CP1L-EL20DR-D PLC with any firmware version accessible from the network, it is likely affected by CVE-2023-22357.
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 dataIsolate affected PLCs on restricted network segments; contact OMRON for patched firmware and apply when available; implement compensating controls such as firewall rules limiting access to authorized endpoints only.
- Consultation6.0 h
- Implementation8.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-22357 — 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-2023-22357 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
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