CVE-2019-9312 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 local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-78288018
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9312 represents a critical out-of-bounds read flaw within the Bluetooth subsystem of Android operating systems. This issue stems from a fundamental missing bounds check in the Bluetooth implementation that processes incoming data packets. The flaw exists at the kernel level where Bluetooth protocol handlers fail to properly validate the length of incoming data structures before attempting to access memory regions. Such missing validation creates a scenario where maliciously crafted Bluetooth packets could trigger memory access violations that potentially expose sensitive information stored in adjacent memory locations. The vulnerability affects Android 10 and earlier versions, with the Android ID A-78288018 documenting the specific implementation details within the Android Bluetooth stack.
The technical exploitation of this vulnerability occurs through Bluetooth protocol parsing mechanisms that handle incoming packets without proper length validation. When a Bluetooth device receives malformed data structures, the missing bounds check allows the processing code to read beyond the allocated memory boundaries of the data buffer. This out-of-bounds read can potentially expose kernel memory contents including sensitive data such as cryptographic keys, session tokens, or other confidential information stored in adjacent memory regions. The vulnerability does not require any user interaction or additional execution privileges for exploitation, making it particularly dangerous as it can be triggered remotely through Bluetooth communication. This characteristic aligns with CWE-129, which specifically addresses improper bounds checking in software implementations, and represents a classic example of how insufficient input validation can lead to information disclosure vulnerabilities.
The operational impact of CVE-2019-9312 extends beyond simple information disclosure as it creates potential pathways for further exploitation. Attackers could leverage this vulnerability to gather intelligence about the target device's memory layout, which could aid in developing more sophisticated attacks targeting other system components. The vulnerability's remote exploitation capability means that adversaries could potentially compromise devices within Bluetooth range without requiring physical access or user interaction. This makes it particularly concerning for mobile devices that maintain continuous Bluetooth connectivity and for IoT devices that rely heavily on Bluetooth communication protocols. The lack of user interaction requirements places this vulnerability in the ATT&CK framework category of initial access through network services, where adversaries can establish footholds without traditional user engagement. The vulnerability affects the confidentiality aspect of the CIA triad by potentially exposing sensitive kernel memory contents that could reveal system internals, authentication mechanisms, or other critical information.
Mitigation strategies for CVE-2019-9312 primarily focus on implementing proper bounds checking mechanisms within the Bluetooth protocol handlers and applying timely security patches from Google. Device manufacturers should ensure that Bluetooth stack implementations include comprehensive input validation for all incoming data structures, particularly those related to Bluetooth protocol headers and payload data. System administrators should disable unnecessary Bluetooth functionality when not required and implement network segmentation to limit potential attack surfaces. The vulnerability demonstrates the importance of robust input validation in kernel-level code and highlights the need for comprehensive security testing of communication protocols. Organizations should also consider implementing Bluetooth monitoring solutions to detect anomalous packet patterns that might indicate exploitation attempts. Regular security updates and vulnerability assessments should be conducted to ensure that Bluetooth implementations remain secure against similar classes of vulnerabilities. The fix typically involves adding proper length validation checks before any memory access operations in the Bluetooth protocol parsing code, ensuring that all data structures are properly bounded before processing.