CVE-2016-6681 in Android
Summary
by MITRE
drivers/misc/qcom/qdsp6v2/audio_utils.c in a Qualcomm QDSP6v2 driver in Android before 2016-10-05 on Nexus 5X, Nexus 6P, and Android One devices does not initialize certain data structures, which allows attackers to obtain sensitive information via a crafted application, aka Android internal bug 30152182 and Qualcomm internal bug CR 1049521.
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Analysis
by VulDB Data Team • 09/22/2022
The vulnerability identified as CVE-2016-6681 resides within the Qualcomm QDSP6v2 audio driver component of Android operating systems, specifically affecting devices such as the Nexus 5X, Nexus 6P, and Android One models. This flaw manifests in the drivers/misc/qcom/qdsp6v2/audio_utils.c file where certain data structures fail to undergo proper initialization before being utilized by the system. The issue represents a classic case of uninitialized memory access that can potentially expose sensitive information to malicious applications. The vulnerability was disclosed alongside Android internal bug 30152182 and Qualcomm internal bug CR 1049521, indicating its significance within the mobile platform security landscape.
The technical nature of this vulnerability stems from improper memory management within the audio processing subsystem of Qualcomm's QDSP6v2 architecture. When applications interact with the audio driver through the QDSP6v2 interface, the driver's audio_utils.c module fails to initialize critical data structures before processing audio commands or responses. This uninitialized memory state can contain residual data from previous operations, potentially including sensitive information such as cryptographic keys, system credentials, or other confidential data that was previously stored in memory locations. The flaw falls under CWE-457: Use of Uninitialized Variable, which is categorized as a fundamental memory management error that can lead to information disclosure vulnerabilities. Attackers can exploit this weakness by crafting malicious applications that trigger the audio driver with specific parameters, causing the uninitialized structures to be read and potentially leaked to the attacker.
The operational impact of CVE-2016-6681 extends beyond simple information disclosure, as it provides attackers with access to potentially sensitive data that could be leveraged for more sophisticated attacks. Mobile devices running affected Android versions become vulnerable to attacks where malicious applications can extract confidential information from the audio driver's memory structures. This vulnerability is particularly concerning in the context of mobile security because audio processing is a common system function that applications frequently utilize, making the attack surface relatively broad. The vulnerability's classification under the ATT&CK framework would align with T1059.001 Command and Scripting Interpreter: PowerShell, though more accurately it represents a system-level information disclosure technique. The exposure of uninitialized memory can potentially lead to credential theft, key extraction, or other sensitive data compromises that could undermine the security posture of affected devices.
Mitigation strategies for CVE-2016-6681 require both immediate and long-term approaches to address the underlying memory initialization issue. The primary solution involves updating affected Android devices to versions that contain the patched Qualcomm QDSP6v2 driver implementation, specifically those released after October 5, 2016. Device manufacturers and carriers should prioritize rolling out security patches to affected Nexus and Android One devices to ensure proper memory initialization occurs before audio processing operations begin. System administrators and security teams should also implement monitoring to detect potential exploitation attempts through unusual audio processing patterns or memory access behaviors. Additionally, application developers should avoid unnecessary reliance on audio processing APIs that might trigger this vulnerability, while security researchers should maintain awareness of similar uninitialized memory issues in other Qualcomm driver components. The fix typically involves ensuring that all data structures within the audio_utils.c module are properly initialized before any processing occurs, thereby preventing the leakage of sensitive information through uninitialized memory access patterns.