CVE-2023-37556
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 · uneditedIn multiple versions of multiple Codesys products, after successful authentication as a user, specific crafted network communication requests with inconsistent content can cause the CmpAppBP component to read internally from an invalid address, potentially leading to a denial-of-service condition. This vulnerability is different to CVE-2023-37552, CVE-2023-37553, CVE-2023-37554 and CVE-2023-37555.
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 confidenceThis is a denial-of-service vulnerability in Codesys products where authenticated users can send crafted network communication requests with inconsistent content, causing the CmpAppBP component to read from an invalid memory address. Successful exploitation renders the service unavailable.
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< 4.10.0.0< 4.10.0.0< 4.10.0.0< 4.10.0.0< 4.10.0.0< 4.10.0.0< 4.10.0.0< 4.10.0.0CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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 the Codesys Control product installedCheck the product name or directory on the system (e.g., /etc/codesys*, /opt/codesys*, or look for codesyscontrol related directories)Affected if The product matches one of the affected products: Beaglebone, Empc A/imx6, IoT2000, Linux, Pfc100, Pfc200, Plcnext, or Raspberry Pi SL
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Determine the installed Codesys Control versionLocate and read the version file or check the runtime version (common locations: /etc/codesys*/version, /opt/codesys*/version, or use system info commands if available)Affected if The installed version is less than 4.10.0.0 (e.g., 4.9.x, 4.8.x, etc.)
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Verify the CmpAppBP component is loadedCheck if the CmpAppBP component is present or active in the Codesys runtime (this may appear in component lists, logs, or runtime diagnostics)Affected if The CmpAppBP component is loaded or enabled in the runtime environment
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Assess network exposure to authenticated attackersReview network configuration and user access controls to determine if unauthenticated or low-privilege users can send network requests to the Codesys serviceAffected if The Codesys network service is accessible to untrusted users or networks without proper authentication controls
A user is affected if they are running any Codesys Control product from the list with version < 4.10.0.0 and the CmpAppBP component is active, with network exposure to potentially untrusted authenticated users.
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.
dbcve · scoped4.10.0.0
Apply vendor patches from Codesys for all affected product versions. Review user access controls and network segmentation to limit exposure to authenticated attackers.
Upgrade to CODESYS Control version 4.10.0.0 or later for all affected products
- 1. Identify all affected CODESYS Control products in your environment (Beaglebone, Empc A/imx6, Iot2000, Linux, Pfc100, Pfc200, Plcnext, Raspberry Pi)
- 2. Check current installed version of CODESYS Control on each device
- 3. For each device running version < 4.10.0.0, obtain the corresponding update package from the official CODESYS vendor (typically from the product download page or vde.com)
- 4. Before upgrading, back up current project files and configurations
- 5. Apply the upgrade to version 4.10.0.0 or later following vendor-specific installation instructions
- 6. After upgrade, verify the CmpAppBP component is functioning and network communication is stable
- 7. Test that the previously vulnerable functionality works correctly post-upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-37556 — 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-2023-37556 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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
- No spam, self-promotion, credentials, or personal data