CVE-2019-9401 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-115375248
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Analysis
by VulDB Data Team • 09/13/2020
This vulnerability resides within the Bluetooth subsystem of Android operating systems, specifically affecting version 10 and potentially earlier releases. The issue stems from a critical missing bounds check in the Bluetooth protocol handling mechanisms, creating a potential attack vector that allows for controlled termination of Bluetooth services. The vulnerability is classified as a remote denial of service condition, meaning an attacker can exploit this weakness without requiring physical access to the device or elevated privileges. This represents a significant security concern as it can be triggered through wireless communication without user interaction, making it particularly dangerous in environments where Bluetooth connectivity is constantly maintained. The absence of user interaction requirements for exploitation aligns with the characteristics of a remote code execution vulnerability, though the specific impact is limited to service termination rather than arbitrary code execution.
The technical flaw manifests as a classic bounds checking vulnerability that allows for memory corruption through malformed Bluetooth packets or protocol sequences. When the Bluetooth stack processes incoming data without proper validation of packet boundaries or buffer limits, it becomes susceptible to overflows or underflows that can cause the system to terminate Bluetooth services abruptly. This type of vulnerability is commonly associated with CWE-129, which addresses insufficient bounds checking, and can be categorized under the broader class of memory safety issues that affect network protocol implementations. The vulnerability's impact is amplified by the fact that Bluetooth is a fundamental component of Android devices, used for connectivity with numerous peripherals and services, making the potential denial of service condition particularly disruptive to device functionality. The exploitation mechanism leverages the inherent trust placed in Bluetooth communication protocols, where malformed packets can trigger unexpected behavior in the underlying implementation.
From an operational perspective, this vulnerability can severely impact device usability and security posture, particularly in enterprise environments where Bluetooth connectivity is essential for device management and peripheral integration. The remote nature of the exploit means that attackers can target vulnerable devices from considerable distances, potentially affecting users in public spaces or corporate environments without requiring proximity or physical access. The lack of privilege requirements makes this vulnerability particularly concerning as it can be exploited by malicious actors with minimal technical expertise. The controlled termination aspect suggests that attackers can potentially predict and manipulate the service termination process, possibly leading to more sophisticated attacks that leverage the service disruption as a stepping stone for additional exploitation. This vulnerability directly impacts the availability aspect of the CIA triad, potentially causing service degradation or complete loss of Bluetooth functionality that users rely upon for connectivity.
Mitigation strategies should focus on implementing proper bounds checking mechanisms within the Bluetooth stack implementation and applying timely security patches from Google and device manufacturers. Organizations should prioritize updating affected Android devices to versions that contain fixes for this vulnerability, as the remote exploitation capability makes immediate remediation essential. Network administrators should consider implementing Bluetooth access controls and monitoring for anomalous Bluetooth traffic patterns that might indicate exploitation attempts. The vulnerability highlights the importance of robust input validation in network protocol implementations and serves as a reminder of the critical need for thorough security testing of core system components. Additionally, implementing network segmentation and access controls for Bluetooth services can help limit the potential impact of exploitation attempts, while continuous monitoring for Bluetooth-related anomalies can provide early detection of potential attacks targeting this vulnerability. The remediation process should also include verification that bounds checking has been properly implemented and tested across all Bluetooth protocol handling components to prevent similar issues from emerging in future implementations.