Ccu3 FirmwareOperating system · Eq 3

CVE-2019-10120

HIGH · 8.8 CVSS v3.0 Published 2019-07-10
Fix available
A fix is available. Upgrade to 2.41.8 / 3.43.16 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
On eQ-3 HomeMatic CCU2 devices before 2.41.8 and CCU3 devices before 3.43.16, automatic login configuration (aka setAutoLogin) can be achieved by continuing to use a session ID after a logout, aka HMCCU-154.

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 eQ-3 HomeMatic CCU2 and CCU3 home automation controllers contain a session fixation vulnerability where session IDs remain valid after logout, allowing attackers to maintain unauthorized access via the setAutoLogin functionality. This enables persistent access even after legitimate users log out of the device.

MitigationUpdate HomeMatic CCU2 firmware to version 2.41.8 or later, and CCU3 firmware to version 3.43.16 or later, to invalidate session IDs properly upon logout.

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
Ccu3 FirmwareOperating system
Affected:< 3.43.16
Ccu2 FirmwareOperating system
Affected:< 2.41.8

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 the installed firmware version on the CCU2 or CCU3 device
    Access the device web interface and navigate to the system information page, or use the 'ls /firmware' command via SSH if available, to retrieve the exact firmware version number
    Affected if The firmware version is below 2.41.8 for CCU2 or below 3.43.16 for CCU3
  2. Confirm the device model is CCU2 or CCU3
    Check the device label or system information page to verify the model is either HomeMatic CCU2 or CCU3
    Affected if The device is an eQ-3 HomeMatic CCU2 or CCU3 controller with a vulnerable firmware version
  3. Verify the setAutoLogin functionality exists
    Examine the device web interface or API endpoints for the setAutoLogin feature, which allows automatic re-authentication without requiring fresh login credentials
    Affected if The setAutoLogin functionality is present and accessible on the device
  4. Test session validity after logout (if you have administrative access)
    Log into the device web interface, note the session identifier, log out, then attempt to use the original session identifier to access protected resources
    Affected if The original session ID remains valid and grants access after logout, indicating session fixation vulnerability

The device is affected if it is a CCU2 running firmware below 2.41.8 or a CCU3 running firmware below 3.43.16, and the setAutoLogin feature allows old session IDs to remain valid after logout.

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 2.41.8 / 3.43.16 or later
Fixed in 2.41.83.43.16
Interim mitigation

Update HomeMatic CCU2 firmware to version 2.41.8 or later, and CCU3 firmware to version 3.43.16 or later, to invalidate session IDs properly upon logout.

Fix this in Ccu3 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,640
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Scan for this in your stack

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dbcve dependency scanner

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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-2019-10120 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