CVE-2020-12834Public exploitNetwork attack vector

Unauthenticated code execution via default WebUI auto-login

Published May 15, 2020 · Updated Aug 4, 2024

Improper authorization in eQ-3 Homematic CCU2 through 2.51.6 and CCU3 through 3.51.6 allows remote attackers to execute code. The WebUI enables automatic login by default after initial setup or a factory reset, exposing a session identifier that can be supplied to ReGa.runScript, whose system.Exec call executes plain Unix commands. Access to the WebUI is required, and successful exploitation grants command execution on the smart-home controller.

CVSS severity9.8
Critical
EPSS probability11.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in eQ-3 Homematic CCU2 through 2.51.6 and CCU3 through 3.51.6 allows remote attackers to execute code. The WebUI enables automatic login by default after initial setup or a factory reset, exposing a session identifier that can be supplied to ReGa.runScript, whose system.Exec call executes plain Unix commands. Access to the WebUI is required, and successful exploitation grants command execution on the smart-home controller.

The record

CVE
CVE-2020-12834
Published
May 15, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-276, T1059
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.3psytesterCVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
T1059Command and Scripting Interpreter

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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