CVE intelligence and bounded remediation
CVE-2019-10121 — eQ-3 HomeMatic CCU2 devices before 2.41.8 and CCU3 devices before 3.43.15 use session IDs for authentication but lack authorization checks
Critical
CVSS 9.8
eQ-3 HomeMatic CCU2 devices before 2.41.8 and CCU3 devices before 3.43.15 use session IDs for authentication but lack authorization checks. An attacker can obtain a session ID via the user authentication dialogue, aka HMCCU-153. This leads to automatic login as admin.
- Severity
- Critical
- CVSS
- 9.8 (3.0)
- Published
- 2019-07-10
- CISA KEV
- Not currently listed
- Ecosystem
- operating-system
- Weaknesses
- CWE-306
Affected products
- eq-3 / ccu3_firmware
- eq-3 / ccu2_firmware
Matched remediation archetype
Authentication bypass and missing authentication
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
- Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
- Review session, token, credential, and proxy trust configuration without attempting account takeover.
Remediate safely
- Apply the supported fix and centralize fail-closed authentication before protected request handling.
- Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
- Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.
Authoritative sources
Complete CVE record and remediation plan
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.