Logo\! 8 Bm FirmwareOperating system · Siemens

CVE-2020-25233

MEDIUM · 5.5 CVSS v3.1 Published 2020-12-14
Fix available
A fix is available. Upgrade to 8.3 or later.
See remediation →
57/100
Remediation priority · Elevated
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 LOGO! 8 BM (incl. SIPLUS variants) (All versions < V8.3). The firmware update of affected devices contains the private RSA key that is used as a basis for encryption of communication with the device.

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 firmware for LOGO! 8 BM devices (versions prior to V8.3) contains a private RSA key embedded in the binary. This private key, intended for encrypted device communication, is distributed publicly with the firmware download. An attacker who obtains the firmware can extract this key and use it to decrypt communications with the device or impersonate the device, enabling man-in-the-middle attacks.

MitigationUpdate LOGO! 8 BM devices to firmware version V8.3 or later, which replaces the compromised private key. Additionally, implement network segmentation and monitor for suspicious device communications given the key exposure in older firmware versions.

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
Logo\! 8 Bm FirmwareOperating system
Affected:< 8.3

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/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 LOGO! 8 BM devices on the network
    Locate all Siemens LOGO! 8 BM devices by reviewing network inventory, asset lists, or using network scanning tools to identify devices with the LOGO! 8 BM product identifier
    Affected if Any LOGO! 8 BM device is present in the environment
  2. Access device firmware version
    Log into the device web interface, use Siemens TIA Portal, or query the device through its management interface to retrieve the current firmware version
    Affected if The displayed firmware version is less than V8.3
  3. Compare version to affected range
    Review the obtained firmware version number and confirm it falls within the affected range of versions prior to V8.3
    Affected if Firmware version is earlier than V8.3 (for example, V8.2, V8.1, V8.0, or earlier)
  4. Verify key rotation status
    If the device was previously on firmware < V8.3 but has been updated, confirm whether the device's RSA key pair has been regenerated after the firmware update to V8.3 or later
    Affected if The device still uses the original embedded key from pre-V8.3 firmware

A user is affected if any LOGO! 8 BM device in their environment is running firmware version earlier than V8.3, as this firmware contains the publicly exposed private RSA key.

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 8.3 or later
Fixed in 8.3
Interim mitigation

Update LOGO! 8 BM devices to firmware version V8.3 or later, which replaces the compromised private key. Additionally, implement network segmentation and monitor for suspicious device communications given the key exposure in older firmware versions.

Fix this in Logo\! 8 Bm Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing6.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,160.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-25233 — 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-2020-25233 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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