Cp 8021 Master Module FirmwareOperating system · Siemens

CVE-2021-46304

HIGH · 7.5 CVSS v3.1 Published 2022-08-10
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 vulnerability has been identified in CP-8000 MASTER MODULE WITH I/O -25/+70°C (All versions), CP-8000 MASTER MODULE WITH I/O -40/+70°C (All versions), CP-8021 MASTER MODULE (All versions), CP-8022 MASTER MODULE WITH GPRS (All versions). The component allows to activate a web server module which provides unauthenticated access to its web pages. This could allow an attacker to retrieve debug-level information from the component such as internal network topology or connected systems.

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 CP-8000/CP-8021/CP-8022 Master Modules contain a web server module that, when activated, provides unauthenticated access to its web pages. This exposes debug-level information including internal network topology and details of connected systems to any network attacker.

MitigationDisable or restrict the web server module, implement authentication for any accessible web interfaces, and apply network segmentation to limit exposure to trusted networks only.

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
Cp 8021 Master Module FirmwareOperating system
Affected:all versions
Cp 8000 Master Module With I\/o 25\/\+70 FirmwareOperating system
Affected:all versions
Cp 8000 Master Module With I\/o 40\/\+70 FirmwareOperating system
Affected:all versions
Cp 8022 Master Module With Gprs 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
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. Confirm device model is affected
    Identify the Siemens Master Module model by checking the device label, firmware banner, or web interface footer for CP-8000, CP-8021, or CP-8022 designations
    Affected if The device is a Siemens CP-8000, CP-8021, or CP-8022 Master Module
  2. Verify web server is enabled
    Access the device configuration or check the web server status page, typically at the device IP on port 80/443, or review the device configuration file for web server module status
    Affected if The web server module shows as enabled or activated in the device configuration
  3. Test for unauthenticated web access
    Open a browser and navigate to the device IP address without providing any login credentials; observe if web pages load without an authentication prompt
    Affected if The web interface loads without requiring any username or password, showing dashboard or status pages directly
  4. Inspect for exposed debug information
    Browse through all available web pages and look for debug sections, network topology diagrams, device lists, or internal system information that should not be publicly accessible
    Affected if Debug-level information such as internal network topology, connected device lists, or system configuration details are visible without authentication

A user is affected if they have a Siemens CP-8000/CP-8021/CP-8022 Master Module with the web server enabled and accessible without authentication, exposing internal network topology or system details.

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

Disable or restrict the web server module, implement authentication for any accessible web interfaces, and apply network segmentation to limit exposure to trusted networks only.

Fix this in Cp 8021 Master Module Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
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Scan for this in your stack

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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-2021-46304 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
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