Apu0200 FirmwareOperating system · Sick

CVE-2023-43699

HIGH · 7.5 CVSS v3.1 Published 2023-10-09
Fix available
A fix is available. Upgrade to 4.0.0.6 or later.
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
Improper Restriction of Excessive Authentication Attempts in RDT400 in SICK APU allows an unprivileged remote attacker to guess the password via trial-and-error as the login attempts are not limited.

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

The SICK APU RDT400 component lacks proper rate limiting or account lockout mechanisms on the authentication function, allowing remote attackers to perform unlimited password guessing attempts via brute-force attacks.

MitigationImplement account lockout after a configurable number of failed login attempts and/or rate limiting on the authentication endpoint to prevent brute-force password guessing.

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
Apu0200 FirmwareOperating system
Affected:< 4.0.0.6

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
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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 APU RDT400 firmware version
    Access the device admin interface or check system information page, or use the device's built-in version check command (typically found in Settings > System > About or via CLI). Compare the displayed firmware version against the affected range: vulnerable if version is lower than 4.0.0.6.
    Affected if Firmware version is below 4.0.0.6 (e.g., 4.0.0.5, 3.x.x, etc.)
  2. Confirm device model is SICK Apu0200
    Verify the device model number through the admin interface, device label, or system information. This CVE specifically affects the Apu0200 model.
    Affected if Device model is SICK Apu0200 with vulnerable firmware version.
  3. Determine if web-based authentication is accessible
    Check if the device's web interface (typically HTTP/HTTPS on ports 80/443 or custom ports) is reachable from network locations. Attempt to access the login page to confirm the authentication endpoint is exposed.
    Affected if The web authentication interface is exposed to network access (not isolated behind strictly controlled access).
  4. Review authentication logs for brute-force patterns
    Examine device logs, especially authentication or security logs, for signs of repeated failed login attempts from the same source IP address within short time periods. Look for patterns indicating unlimited guessing.
    Affected if Logs show multiple failed login attempts from the same source without account lockout or throttling occurring.

Your environment is affected if you have a SICK Apu0200 device running firmware version lower than 4.0.0.6 with its web authentication interface accessible to network users.

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
Upgrade available Upgrade to 4.0.0.6 or later
Fixed in 4.0.0.6
Interim mitigation

Implement account lockout after a configurable number of failed login attempts and/or rate limiting on the authentication endpoint to prevent brute-force password guessing.

Fix this in Apu0200 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing3.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,050
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,880.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-43699 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-43699 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