CVE-2019-9422 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 information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-111214766
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Analysis
by VulDB Data Team • 09/13/2020
The vulnerability identified as CVE-2019-9422 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 subsystem that processes incoming data packets. The flaw exists at the protocol parsing layer where the system fails to validate the length or boundaries of incoming Bluetooth frames before attempting to access memory locations. Such a missing validation mechanism creates a predictable attack surface that allows malicious actors to craft specifically formatted Bluetooth packets designed to trigger the out-of-bounds memory access.
The technical nature of this vulnerability places it squarely within the CWE-129 category of "Improper Input Validation" and more specifically aligns with CWE-125 "Out-of-bounds Read" which is classified under the broader weakness of insufficient boundary checking. This vulnerability operates at the system level within the Bluetooth stack, where legitimate Bluetooth communication protocols are parsed and processed. The flaw manifests when the Bluetooth subsystem receives malformed or specially crafted data that exceeds expected buffer boundaries, causing the processor to read memory locations outside the intended data structure. This type of vulnerability is particularly dangerous because it can be exploited remotely without requiring any user interaction or additional privileges, making it a prime target for automated exploitation campaigns.
From an operational perspective, the impact of CVE-2019-9422 extends beyond simple information disclosure to potentially enable more sophisticated attacks. While the primary vector appears to be remote information disclosure, the out-of-bounds read could potentially be leveraged to extract sensitive data from adjacent memory regions, including cryptographic keys, session tokens, or other confidential information stored in memory. The vulnerability affects Android 10 systems specifically, which represents a significant portion of mobile devices that were in use during the time this vulnerability was prevalent. The lack of user interaction requirements means that devices could be compromised simply by being within range of an attacker's Bluetooth transmission, making it particularly concerning for mobile environments where users frequently encounter unknown Bluetooth devices.
The exploitation of this vulnerability aligns with several techniques documented in the MITRE ATT&CK framework, specifically under the T1059.001 technique for command and control through Bluetooth protocols. The vulnerability also relates to the T1071.004 category of application layer protocol usage for network communication. Security researchers have noted that this type of memory corruption vulnerability often serves as a stepping stone for more complex attacks, potentially enabling privilege escalation or remote code execution if combined with other vulnerabilities. The Android ID A-111214766 indicates that this vulnerability was properly tracked within Google's security framework, demonstrating the recognized severity of the issue. Organizations should prioritize patching affected Android 10 devices as soon as possible, as the vulnerability represents a persistent risk that can be exploited without user awareness or consent. The remediation process involves updating the Bluetooth stack implementation to include proper bounds checking mechanisms and validation routines that prevent memory access violations.