CVE-2019-9389 in Android
Summary
by MITRE
In Bluetooth, there is a possible out of bounds read 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-117567058
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Analysis
by VulDB Data Team • 09/13/2020
The vulnerability identified as CVE-2019-9389 represents a critical out-of-bounds read flaw within the Bluetooth implementation of Android 10 systems. This issue stems from a fundamental missing bounds check in the Bluetooth protocol handling code, creating a scenario where malicious actors can trigger memory access violations without requiring any special privileges or user interaction. The vulnerability resides in the core Bluetooth stack implementation, specifically affecting how the system processes incoming Bluetooth packets and handles buffer operations. This type of flaw falls under the CWE-129 category of Improper Validation of Array Index, which directly relates to the absence of proper bounds checking mechanisms that should validate array access operations.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it creates potential for more sophisticated exploitation scenarios. An attacker positioned within the Bluetooth range of an affected device can craft malicious Bluetooth packets that trigger the out-of-bounds read condition, causing the Bluetooth service to crash and potentially leading to a complete system freeze or reboot. This remote exploitation capability without user interaction makes the vulnerability particularly dangerous in environments where Bluetooth connectivity is constantly active, such as smartphones, tablets, and IoT devices. The flaw operates at the kernel level within the Bluetooth subsystem, making it difficult to detect and mitigate through standard application-level security measures.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1105 for remote access tools, as it enables remote code execution potential through Bluetooth protocol manipulation. The lack of user interaction requirements places this vulnerability in the category of zero-click exploits, making it highly attractive to threat actors seeking to compromise devices without detection. The Android ID A-117567058 indicates this was properly tracked within Google's security infrastructure, highlighting the severity of the issue. The vulnerability affects all Android 10 devices and could potentially impact older versions if they share similar Bluetooth implementation patterns.
Mitigation strategies for CVE-2019-9389 primarily involve applying the latest security patches released by Google and device manufacturers, which include proper bounds checking implementations and memory validation routines. System administrators should implement Bluetooth disabling policies for devices that do not require wireless connectivity, particularly in high-security environments. Network monitoring solutions should be configured to detect anomalous Bluetooth traffic patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of input validation in embedded systems and wireless protocols, emphasizing the need for robust memory safety practices in mobile operating systems. Organizations should also consider implementing device firmware updates and regular security assessments to identify similar vulnerabilities in their Bluetooth implementations, as this type of flaw often indicates broader architectural weaknesses in protocol handling code.