CVE-2019-9394 in Android
Summary
by MITRE
In Bluetooth, there is possible controlled termination due to a missing bounds check. This could lead to remote denial of service with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-116351796
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Analysis
by VulDB Data Team • 09/13/2020
The vulnerability identified as CVE-2019-9394 represents a critical flaw in Android's Bluetooth implementation that stems from a missing bounds check during controlled termination scenarios. This issue manifests within the Bluetooth subsystem where improper validation of input parameters during connection termination processes creates opportunities for malicious exploitation. The vulnerability specifically affects Android 10 and is catalogued under Android ID A-116351796, highlighting its significance within the mobile operating system's security framework.
The technical nature of this flaw places it squarely within the realm of software boundary checking failures, which aligns with CWE-129, representing an insufficient bounds check. The missing bounds validation during Bluetooth connection termination allows attackers to craft malicious packets or connection states that can trigger unexpected behavior in the Bluetooth stack. This particular vulnerability demonstrates how seemingly routine operations like connection termination can become attack vectors when proper input validation is absent. The flaw operates at the kernel level within Bluetooth subsystem components where connection state management and resource cleanup procedures are handled.
From an operational perspective, this vulnerability presents a severe remote denial of service threat that can be exploited without any additional privileges or user interaction requirements. The absence of user interaction requirements significantly broadens the attack surface, as malicious actors can initiate exploitation remotely without needing physical access or user engagement. This characteristic places the vulnerability in the ATT&CK framework under the T1499 category of Network Denial of Service, where adversaries can leverage Bluetooth protocols to disrupt normal device operations. The remote exploitability combined with the lack of privilege requirements makes this vulnerability particularly dangerous in mobile environments where Bluetooth connectivity is constantly maintained.
The potential impact extends beyond simple service disruption to encompass broader system stability and user experience degradation. When exploited successfully, the vulnerability can cause Bluetooth services to crash or become unresponsive, effectively disabling wireless connectivity features that users rely on for communication, data transfer, and device pairing operations. This disruption can cascade into affecting other system components that depend on Bluetooth functionality, creating a more widespread service degradation across the device. The vulnerability's exploitation can occur during normal Bluetooth operation, making it particularly insidious as users may not immediately recognize the service disruption or understand its origin.
Mitigation strategies for CVE-2019-9394 primarily focus on applying security patches provided by Google and device manufacturers, as the vulnerability resides in the core Bluetooth implementation within Android. System administrators and users should prioritize updating to patched Android versions that address the missing bounds check in Bluetooth termination procedures. Additionally, organizations should implement monitoring for unusual Bluetooth connection patterns or service disruptions that might indicate exploitation attempts. Network segmentation and Bluetooth disabling in non-essential environments can serve as temporary protective measures while patches are deployed. The vulnerability underscores the importance of rigorous input validation in security-critical system components and demonstrates how fundamental boundary checking can prevent remote denial of service scenarios.