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Lms531 FirmwareOperating system · Sick

CVE-2023-4418

HIGH · 7.5 CVSS v3.1 Published 2023-08-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 · unedited
A remote unprivileged attacker can sent multiple packages to the LMS5xx to disrupt its availability through a TCP SYN-based denial-of-service (DDoS) attack. By exploiting this vulnerability, an attacker can flood the targeted LMS5xx with a high volume of TCP SYN requests, overwhelming its resources and causing it to become unresponsive or unavailable for legitimate users.

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 confidence

This is a denial-of-service vulnerability in LMS5xx devices where an unauthenticated remote attacker can overwhelm the device by flooding it with TCP SYN requests, exhausting its resources and making it unavailable to legitimate users.

MitigationImplement network-level protections such as rate limiting, SYN cookies, or firewall rules to filter malicious SYN traffic; also check vendor for firmware updates that may address TCP handling improvements.

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
Lms531 FirmwareOperating system
Affected:all versions
Lms511 FirmwareOperating system
Affected:all versions
Lms500 FirmwareOperating system
Affected:all versions

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Sick LMS device on the network
    Use network scanning (e.g., nmap, network inventory tools) to discover devices with vendor identifier 'Sick' and model LMS531, LMS511, or LMS500. Check device management interface, DHCP logs, or physical labeling.
    Affected if A Sick LMS531, LMS511, or LMS500 sensor is found on the network.
  2. Check device firmware version
    Access the device web interface or use SNMP/CLI to query the firmware version. Common paths: Device Status page, 'Info' or 'System' menu in web UI, or command output like 'show version'.
    Affected if Any firmware version is returned - the advisory states all versions are affected.
  3. Verify TCP network services are exposed
    Scan the device with nmap: 'nmap -sS -p 1-1000 <device-ip>' to identify open TCP ports. Check if the device has HTTP (80/443) or other TCP services accessible.
    Affected if The device has TCP services listening on network-accessible interfaces.
  4. Assess network exposure
    Review firewall rules, ACLs, and network topology to determine if the LMS device is reachable from untrusted networks (internet-facing, guest networks, or DMZ without proper filtering).
    Affected if The device is directly accessible from the internet or untrusted networks without network-level protection.
  5. Check for signs of SYN flood symptoms
    Monitor the device or upstream network gear for high connection counts, CPU/network utilization spikes, or device unresponsiveness. Use 'netstat -an' on adjacent devices or check device logs for connection errors.
    Affected if The device shows symptoms of resource exhaustion from excessive SYN requests.

If you have a Sick LMS531, LMS511, or LMS500 device with any firmware version that is network-accessible, your environment is affected by this vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement network-level protections such as rate limiting, SYN cookies, or firewall rules to filter malicious SYN traffic; also check vendor for firmware updates that may address TCP handling improvements.

Fix this in Lms531 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-4418 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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