CVE-2014-9892 in Android
Summary
by MITRE
The snd_compr_tstamp function in sound/core/compress_offload.c in the Linux kernel through 4.7, as used in Android before 2016-08-05 on Nexus 5 and 7 (2013) devices, does not properly initialize a timestamp data structure, which allows attackers to obtain sensitive information via a crafted application, aka Android internal bug 28770164 and Qualcomm internal bug CR568717.
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Analysis
by VulDB Data Team • 08/27/2025
The snd_compr_tstamp function in the Linux kernel's sound subsystem presents a critical information disclosure vulnerability that affects kernel versions through 4.7 and specifically impacts Android devices released before August 5, 2016. This vulnerability stems from improper initialization of a timestamp data structure within the compress offload audio functionality, creating a pathway for attackers to extract sensitive information from kernel memory. The flaw exists in the sound/core/compress_offload.c file, which handles compressed audio offloading operations commonly used in mobile audio processing pipelines. The vulnerability is particularly concerning as it affects devices including the Nexus 5 and Nexus 7 (2013) models, which were widely deployed and represent significant portions of the Android ecosystem during that timeframe. The issue manifests when a malicious application attempts to interact with the compressed audio offload interface without properly initializing the timestamp structure, leading to information leakage through uninitialized memory contents.
This vulnerability maps directly to CWE-119 Improper Access to Memory Location and CWE-248 Uncaught Exception, as it represents an improper handling of uninitialized memory structures that can be exploited to extract kernel memory contents. The attack vector involves crafting a malicious application that invokes the snd_compr_tstamp function with malformed parameters, causing the kernel to return uninitialized timestamp data to user-space applications. The operational impact extends beyond simple information disclosure, as the leaked memory contents may include kernel pointers, stack data, or other sensitive information that could be leveraged for further exploitation. The vulnerability is particularly dangerous in the context of Android's security model where applications typically operate with limited privileges but can still interact with kernel interfaces through system calls, creating a potential attack surface that adversaries could exploit to gain deeper insights into the kernel's memory layout.
The security implications of this vulnerability align with ATT&CK technique T1005 Data from Local System, where adversaries can extract information from the target system by exploiting kernel-level flaws. The information disclosure could potentially reveal kernel memory addresses, which would aid in bypassing kernel address space layout randomization (ASLR) protections, or expose sensitive data structures that could be used to craft more sophisticated attacks. The vulnerability affects the Android operating system's security model by weakening the isolation between user-space applications and kernel-space operations, particularly in the audio subsystem where compressed audio offload is commonly used for multimedia applications. This weakness creates an opportunity for attackers to gather intelligence about the kernel's memory layout, which could be instrumental in developing exploits against other kernel vulnerabilities or in bypassing security mitigations.
Mitigation strategies for this vulnerability should focus on both immediate patching and architectural improvements to prevent similar issues. The primary solution involves applying kernel patches that properly initialize the timestamp data structure before returning it to user-space applications, ensuring that all memory fields are explicitly set to known values. System administrators and device manufacturers should prioritize updating affected Android versions to include the kernel patches that address this specific issue. Additionally, implementing proper input validation and memory initialization practices within the audio subsystem can prevent similar vulnerabilities from emerging in the future. The fix should include ensuring that all data structures passed between kernel and user-space are properly initialized, which aligns with secure coding practices recommended by the CERT Secure Coding Standards. Organizations should also consider implementing monitoring for unusual audio subsystem activity that could indicate exploitation attempts, as the vulnerability requires active exploitation through crafted applications rather than passive attacks, making it somewhat more difficult to detect but still potentially dangerous in the hands of determined attackers.