CVE-2016-2068 in Android
Summary
by MITRE
The MSM QDSP6 audio driver (aka sound driver) for the Linux kernel 3.x, as used in Qualcomm Innovation Center (QuIC) Android contributions for MSM devices and other products, allows attackers to gain privileges or cause a denial of service (integer overflow, and buffer overflow or buffer over-read) via a crafted application that performs a (1) AUDIO_EFFECTS_WRITE or (2) AUDIO_EFFECTS_READ operation, aka Qualcomm internal bug CR1006609.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 09/01/2022
The vulnerability CVE-2016-2068 represents a critical security flaw in the MSM QDSP6 audio driver component of the Linux kernel version 3.x series. This driver serves as the foundational audio processing layer for Qualcomm MSM (Multi-System Module) devices, which are widely deployed in Android smartphones and tablets through Qualcomm Innovation Center contributions. The affected driver operates within the kernel space, handling audio effects processing through specific ioctl operations that allow user-space applications to interact with the underlying audio hardware. This particular vulnerability stems from inadequate input validation and memory management within the audio driver's handling of effects operations, creating multiple attack vectors that can be exploited by malicious applications.
The technical implementation of this vulnerability manifests through two distinct but related attack vectors that exploit different memory corruption mechanisms within the audio driver. The first vector involves the AUDIO_EFFECTS_WRITE operation where a crafted application can trigger an integer overflow condition, leading to improper memory allocation calculations. This overflow can cause subsequent buffer overflow or buffer over-read conditions when the driver attempts to process audio effects data. The second vector operates through AUDIO_EFFECTS_READ operations where similar memory handling flaws can be exploited to cause similar corruption patterns. These vulnerabilities are particularly dangerous because they operate within the kernel space, meaning successful exploitation can result in privilege escalation from user-level applications to kernel-level privileges, potentially allowing attackers to execute arbitrary code with the highest system permissions.
The operational impact of CVE-2016-2068 extends beyond simple denial of service scenarios to encompass full system compromise capabilities. Attackers who successfully exploit these vulnerabilities can leverage the integer overflow conditions to manipulate memory layouts and potentially execute arbitrary code within kernel space. This represents a severe privilege escalation vulnerability that aligns with CWE-190, which specifically addresses integer overflow conditions that can lead to memory corruption. The vulnerability affects devices running Android versions that incorporate Qualcomm's MSM QDSP6 audio driver implementations, making it particularly concerning for mobile device security. The attack surface is significant as any application with the necessary permissions can potentially trigger these conditions, and the exploitation requires minimal privileges beyond what is normally available to standard Android applications. This vulnerability was internally tracked by Qualcomm as CR1006609, highlighting the company's recognition of its severity.
Mitigation strategies for CVE-2016-2068 primarily focus on patching the affected kernel components and implementing proper input validation within the audio driver. System administrators and device manufacturers should prioritize applying the official kernel patches that address the integer overflow conditions in the MSM QDSP6 driver. The fix typically involves implementing proper bounds checking and integer overflow protection mechanisms within the audio effects processing code, ensuring that all buffer operations are properly validated before memory allocation occurs. Additionally, implementing kernel hardening measures such as stack canaries, address space layout randomization, and kernel address space protection can provide additional defense-in-depth layers. Organizations should also consider implementing application whitelisting policies that restrict which applications can perform audio effects operations, and monitoring for suspicious patterns of audio driver usage that might indicate exploitation attempts. This vulnerability demonstrates the importance of thorough input validation in kernel drivers and aligns with ATT&CK techniques related to privilege escalation through kernel vulnerabilities, specifically targeting the kernel rootkit and privilege escalation tactics that attackers use to gain persistent system access.