CVE-2019-12944 in Glue Smart Lock
Summary
by MITRE
Glue Smart Lock 2.7.8 devices do not properly block guest access in certain situations where the network connection is unavailable.
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Analysis
by VulDB Data Team • 01/08/2024
The vulnerability identified as CVE-2019-12944 affects Glue Smart Lock devices running firmware version 2.7.8 and potentially earlier versions. This security flaw represents a critical weakness in the access control mechanisms of smart locking systems, specifically impacting the device's ability to maintain proper authentication states when network connectivity is disrupted. The issue manifests when the network connection becomes unavailable, creating a scenario where guest access permissions are not properly enforced, potentially allowing unauthorized individuals to gain entry to protected facilities.
The technical root cause of this vulnerability lies in the improper handling of authentication states during network disconnection events. When the smart lock loses connectivity to its primary network infrastructure, the device fails to maintain the integrity of its access control policies, particularly regarding guest user permissions. This represents a failure in the device's state management and authentication logic, where the system does not properly transition to a secure offline mode or maintain the last known valid access permissions. The flaw demonstrates poor implementation of fallback security mechanisms that should ensure continued enforcement of access controls even when network connectivity is compromised.
From an operational impact perspective, this vulnerability creates a significant security risk for facilities relying on Glue Smart Lock systems for physical access control. The scenario becomes particularly dangerous when network outages occur during critical periods, as unauthorized individuals could potentially exploit the temporary loss of network connectivity to bypass guest access restrictions. This vulnerability directly violates fundamental security principles of least privilege and defense in depth, as the device fails to maintain its security posture during network disruption events. The risk is amplified in environments where guest access is strictly controlled, as the vulnerability could allow unauthorized individuals to gain physical access to restricted areas during network maintenance, outages, or other connectivity issues.
The vulnerability aligns with CWE-307, which addresses improper restriction of excessive authenticated privileges, and demonstrates characteristics similar to CWE-310, concerning cryptographic issues in authentication mechanisms. From an adversarial perspective, this flaw maps to ATT&CK technique T1078.004, which covers cloud service account manipulation, as the vulnerability essentially allows unauthorized access through compromised authentication states. Organizations using these devices face potential compromise of physical security boundaries, with the risk of unauthorized access increasing during network maintenance windows or unexpected connectivity disruptions. The impact extends beyond simple unauthorized entry, as the vulnerability could enable attackers to gain persistent access to facilities during network outages, potentially leading to data breaches or physical security incidents.
Mitigation strategies should include immediate firmware updates from the vendor to address the authentication state handling issue, implementation of network monitoring to detect connectivity disruptions, and configuration of redundant authentication methods to ensure access control remains effective during network outages. Organizations should also establish procedures for verifying access control states during network restoration events and consider implementing additional physical security measures as compensating controls. The vulnerability underscores the importance of designing security-critical IoT devices with robust offline security mechanisms and proper state management, particularly for systems handling physical access control where failure could result in significant physical security breaches.