CVE-2016-6695 in Android
Summary
by MITRE
sound/soc/msm/qdsp6v2/msm-ds2-dap-config.c in a Qualcomm QDSP6v2 driver in Android before 2016-10-05 allows attackers to cause a denial of service or possibly have unspecified other impact via a crafted visualizer data length, aka Qualcomm internal bug CR 1033540.
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Analysis
by VulDB Data Team • 09/22/2022
The vulnerability identified as CVE-2016-6695 resides within the Qualcomm QDSP6v2 driver component of Android systems, specifically in the msm-ds2-dap-config.c file located in the sound/soc/msm/qdsp6v2 directory. This flaw affects Android versions prior to 2016-10-05 and represents a critical security weakness that could be exploited by malicious actors to compromise system stability and potentially execute unauthorized operations. The vulnerability manifests through improper handling of visualizer data length parameters, creating a pathway for attackers to manipulate the system's audio processing capabilities.
The technical implementation of this vulnerability stems from inadequate input validation within the QDSP6v2 audio driver subsystem. When the system processes visualizer data, it fails to properly validate the length parameter of the crafted input data, allowing an attacker to supply malformed or excessively long data structures. This condition creates a buffer over-read scenario that can lead to memory corruption and system instability. The flaw operates at the kernel level within the audio subsystem, making it particularly dangerous as it can be exploited without requiring elevated privileges or user interaction. The vulnerability aligns with CWE-129, which describes improper validation of length parameters, and represents a classic example of insufficient input validation that can lead to denial of service conditions.
The operational impact of CVE-2016-6695 extends beyond simple system disruption to potentially enable more sophisticated attacks. While the primary effect is a denial of service that can render audio functionality unusable, the vulnerability may also provide opportunities for privilege escalation or information disclosure. Attackers can leverage this weakness to repeatedly crash the audio subsystem, causing persistent system instability that affects user experience and potentially creating conditions for further exploitation. The vulnerability affects devices running Android versions before the specified patch date, leaving millions of devices exposed to potential compromise through this audio processing pathway.
Mitigation strategies for this vulnerability require immediate deployment of the security patches released by Qualcomm and Android developers. System administrators should prioritize updating all affected devices to versions that include the corrected msm-ds2-dap-config.c implementation with proper input validation. The fix involves implementing robust parameter validation that checks visualizer data length against predefined maximum limits and rejects any input that exceeds acceptable boundaries. Additionally, organizations should implement monitoring solutions to detect unusual audio processing patterns that might indicate exploitation attempts. Security teams should consider implementing network-level controls to prevent exploitation attempts and establish incident response procedures for potential exploitation events. This vulnerability demonstrates the importance of comprehensive input validation in kernel-level drivers and highlights the need for continuous security assessments of embedded system components. The remediation process should include thorough testing to ensure that the patched implementation does not introduce regressions in audio functionality while maintaining the security hardening measures.