CVE-2022-46480 in UL3 2nd Gen Smart Lock
Summary
by MITRE • 12/05/2023
Incorrect Session Management and Credential Re-use in the Bluetooth LE stack of the Ultraloq UL3 2nd Gen Smart Lock Firmware 02.27.0012 allows an attacker to sniff the unlock code and unlock the device whilst within Bluetooth range.
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Analysis
by VulDB Data Team • 12/23/2023
The vulnerability identified as CVE-2022-46480 represents a critical weakness in the Bluetooth low energy stack implementation of the Ultraloq UL3 2nd Generation smart lock firmware version 02.27.0012. This flaw manifests through improper session management and credential re-use mechanisms that fundamentally compromise the security posture of the device. The vulnerability enables attackers to perform passive eavesdropping operations within the Bluetooth range of the device, allowing them to capture unlock codes and subsequently gain unauthorized physical access to the secured premises.
The technical root cause of this vulnerability stems from inadequate session handling within the Bluetooth LE protocol stack of the smart lock. Specifically, the firmware fails to implement proper session key rotation and authentication binding mechanisms that would normally prevent credential re-use across multiple connections. This weakness creates a persistent attack surface where an attacker can capture a legitimate unlock sequence during one connection attempt and replay it against the device during subsequent attempts. The flaw aligns with CWE-305 authentication bypass vulnerabilities and represents a failure to properly implement the principle of least privilege in session management. The Bluetooth LE protocol stack in the affected firmware version demonstrates poor cryptographic implementation where session tokens are not adequately randomized or time-bound, making them susceptible to replay attacks.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass broader security implications for physical security infrastructure. An attacker within Bluetooth range can exploit this vulnerability without requiring any specialized equipment beyond standard Bluetooth monitoring tools, making the attack surface extremely broad and accessible. The vulnerability affects the fundamental security model of the smart lock, as it undermines the core assumption that each unlock attempt should be authenticated independently with fresh credentials. This creates a persistent risk where a single captured unlock sequence can be used repeatedly to gain access to the secured location. The vulnerability also has implications for privacy and data integrity, as it may allow attackers to capture and potentially analyze multiple unlock patterns that could reveal user behavior or access frequency. The attack can be executed without any physical contact or specialized knowledge of the device's internal workings, making it particularly dangerous for environments where physical security is paramount.
Mitigation strategies for CVE-2022-46480 should prioritize immediate firmware updates from the manufacturer to address the session management flaws in the Bluetooth LE stack. Organizations should implement network segmentation and monitoring to detect unusual Bluetooth activity patterns that might indicate an active attack. Physical security measures including the installation of additional access control layers and the implementation of multi-factor authentication should be considered as compensating controls. Security teams should also conduct comprehensive vulnerability assessments of all Bluetooth-enabled smart locks within their infrastructure to identify similar implementation flaws. The remediation process should include proper key management protocols, implementation of time-based session tokens, and cryptographic binding of authentication credentials to specific connection sessions. Additionally, organizations should establish monitoring procedures to detect and alert on repeated Bluetooth connection attempts and unauthorized access events that could indicate exploitation of this vulnerability. This vulnerability demonstrates the critical importance of proper session management in IoT devices and aligns with ATT&CK technique T1566.002 for credential harvesting through network sniffing operations.