CVE-2019-9583 in Homematic CCU2
Summary
by MITRE
eQ-3 Homematic CCU2 and CCU3 obtain session IDs without login. This allows a Denial of Service and is a starting point for other attacks. Affected versions for CCU2: 2.35.16, 2.41.5, 2.41.8, 2.41.9, 2.45.6, 2.45.7, 2.47.10, 2.47.12, 2.47.15. Affected versions for CCU3: 3.41.11, 3.43.16, 3.45.5, 3.45.7, 3.47.10, 3.47.15.
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Analysis
by VulDB Data Team • 11/25/2023
The vulnerability identified as CVE-2019-9583 affects eQ-3 Homematic CCU2 and CCU3 home automation controllers, representing a critical authentication flaw that undermines the security posture of these devices. This issue stems from the improper session management implementation where the system generates session identifiers without requiring valid user authentication, creating a fundamental weakness in the access control mechanism. The vulnerability allows unauthorized parties to obtain valid session IDs simply by accessing the device's web interface, bypassing the standard authentication process entirely.
The technical flaw manifests in the session ID generation logic where the system fails to validate user credentials before creating and returning session tokens to clients. This design oversight enables attackers to establish authenticated sessions without providing valid credentials, effectively creating a backdoor into the system. The implementation of this vulnerability aligns with CWE-305 authentication bypass weakness, where the authentication mechanism fails to properly validate user identity before granting access privileges. The flaw exists at the application layer and specifically impacts the web-based management interface of these home automation controllers, making it accessible through standard web browser interactions.
The operational impact of this vulnerability extends beyond simple unauthorized access, creating a foundation for more sophisticated attacks and operational disruption. An attacker who obtains a valid session ID can perform various malicious activities including but not limited to modifying device configurations, accessing sensitive data, or launching denial of service attacks against the device itself. The vulnerability's potential for denial of service stems from the ability to create multiple invalid sessions that could exhaust system resources or disrupt legitimate user access. This vulnerability also serves as a launching point for additional attacks, as the attacker can escalate privileges or access other system components once they have a valid session token, potentially leading to complete system compromise.
The security implications of CVE-2019-9583 are particularly concerning for home automation environments where these devices often control critical infrastructure such as lighting, heating, security systems, and other connected home appliances. The vulnerability's presence in multiple firmware versions across both CCU2 and CCU3 platforms indicates a widespread issue affecting numerous deployments. Organizations and individuals using these devices face significant risk as the vulnerability allows for persistent unauthorized access that could remain undetected for extended periods. The attack surface is further expanded by the fact that these devices are typically accessible from both local networks and potentially the internet, increasing the likelihood of exploitation.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from eQ-3 to address the session management flaw, while also implementing network segmentation to limit access to these devices. Security controls should include disabling unnecessary web interfaces, implementing strong network access controls, and monitoring for unusual session activity. The vulnerability's classification under ATT&CK technique T1078 legitimate credentials demonstrates the importance of proper session management and authentication controls. Organizations should also consider implementing intrusion detection systems to monitor for unauthorized session establishment and ensure that all devices are running patched firmware versions. Regular security assessments and network monitoring are essential to detect any exploitation attempts and maintain the integrity of home automation ecosystems.