CVE-2019-9259 in Android
Summary
by MITRE
In the Bluetooth stack, there is a possible out of bounds write due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-113575306
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9259 represents a critical security flaw within the Android Bluetooth stack that manifests as an out-of-bounds write condition stemming from a use-after-free error. This vulnerability exists in the Android operating system version 10 and affects the underlying Bluetooth communication protocols that handle device pairing and data transmission. The flaw occurs when the system attempts to write data to memory locations that have already been freed, creating a scenario where arbitrary memory locations can be overwritten with malicious data. This particular vulnerability is classified under CWE-416 which specifically addresses use-after-free conditions, making it a well-documented and dangerous class of memory corruption vulnerability that has been exploited in numerous security incidents throughout the mobile platform landscape.
The exploitation of this vulnerability requires only local system execution privileges, meaning that an attacker with minimal access to the device can leverage this flaw to achieve privilege escalation. The absence of user interaction requirements makes this vulnerability particularly concerning as it can be triggered automatically during normal Bluetooth operations without any explicit user consent or awareness. When the Bluetooth stack processes certain malformed packets or executes specific sequence of operations, the freed memory structures become available for reuse, but the system continues to reference them in subsequent operations, leading to the out-of-bounds write condition. This behavior aligns with ATT&CK technique T1068 which describes the exploitation of legitimate credentials and system privileges to gain elevated access, though in this case the escalation occurs through memory corruption rather than credential theft.
The operational impact of CVE-2019-9259 extends beyond simple privilege escalation as it can potentially allow attackers to execute arbitrary code with system-level privileges, effectively compromising the entire device. The Bluetooth subsystem is integral to Android's functionality, handling everything from wireless connectivity to peripheral device communications, making this vulnerability a prime target for attackers seeking persistent access to mobile devices. Once escalated to system privileges, an attacker could potentially access all device data, install malicious applications, modify system configurations, or even disable security features. This vulnerability demonstrates the critical importance of memory safety in mobile operating systems and highlights how seemingly isolated Bluetooth stack components can create pathways for complete system compromise. The vulnerability's presence in Android 10 indicates that it was likely present in multiple versions of the Android platform, making it a widespread concern for device manufacturers and security researchers working to maintain mobile device security across various Android versions.
Mitigation strategies for CVE-2019-9259 should focus on immediate patch deployment through official Android security updates, as Google has released fixes for this vulnerability in subsequent Android security patches. System administrators and device manufacturers should prioritize the deployment of these updates across all affected devices to prevent exploitation. Additionally, organizations should consider implementing network monitoring solutions that can detect anomalous Bluetooth activity patterns that might indicate exploitation attempts. The vulnerability underscores the need for robust memory safety practices in mobile operating system development and highlights the importance of regular security audits of core system components. Security teams should also implement proper device hardening measures, including disabling unnecessary Bluetooth functionality when not required, and maintaining strict network segmentation to limit the potential impact of successful exploitation attempts.