CVE-2019-19192 in BLE Stack
Summary
by MITRE
The Bluetooth Low Energy implementation on STMicroelectronics BLE Stack through 1.3.1 for STM32WB5x devices does not properly handle consecutive Attribute Protocol (ATT) requests on reception, allowing attackers in radio range to cause an event deadlock or crash via crafted packets.
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Analysis
by VulDB Data Team • 03/30/2024
The vulnerability identified as CVE-2019-19192 affects the Bluetooth Low Energy implementation within STMicroelectronics BLE Stack version 1.3.1 and earlier, specifically impacting STM32WB5x devices. This flaw resides in the Attribute Protocol (ATT) handling mechanism, which is a fundamental component of the Bluetooth Low Energy stack responsible for managing data exchange between connected devices. The issue manifests when the system receives consecutive ATT requests without proper handling of the request sequence, creating a condition that can be exploited by remote attackers within radio range. The vulnerability represents a critical weakness in the protocol implementation that undermines the reliability and stability of Bluetooth Low Energy communications.
The technical flaw stems from inadequate state management within the ATT protocol handler, where consecutive requests are not properly sequenced or validated before processing. When multiple ATT requests arrive in quick succession, the system fails to maintain proper event handling flow, leading to a deadlock condition or complete system crash. This occurs because the implementation does not adequately check for pending requests or maintain proper synchronization between request processing and response generation. The vulnerability is particularly concerning as it operates at the protocol level, meaning that an attacker can exploit it without requiring physical access or complex preconditions beyond radio proximity.
The operational impact of this vulnerability extends beyond simple system crashes, as it can lead to complete service disruption for Bluetooth Low Energy devices in the affected range. Attackers can leverage this weakness to perform denial of service attacks against connected devices, potentially affecting critical infrastructure applications such as industrial sensors, medical devices, or automotive systems that rely on Bluetooth Low Energy connectivity. The vulnerability affects devices that operate within the STM32WB5x family, which are commonly used in IoT applications where continuous connectivity is essential. The remote exploitation capability makes this particularly dangerous in environments where devices are deployed without physical security controls, as attackers can target multiple devices simultaneously without requiring specialized equipment.
Mitigation strategies for CVE-2019-19192 should focus on immediate firmware updates from STMicroelectronics, as the vendor has released patches addressing the specific ATT handling issue. Organizations should implement network segmentation to limit the attack surface and reduce the potential impact of exploitation. Additionally, monitoring systems should be deployed to detect unusual patterns in Bluetooth Low Energy traffic that might indicate exploitation attempts. The vulnerability aligns with CWE-1210, which addresses improper handling of concurrent operations, and maps to ATT&CK technique T1059.001 for remote code execution through protocol manipulation. Regular security assessments and vulnerability scanning should be conducted to identify affected devices, while implementing proper input validation and state management protocols can help prevent similar issues in future implementations.