CVE-2017-11046 in Android
Summary
by MITRE
In Android for MSM, Firefox OS for MSM, QRD Android, with all Android releases from CAF using the Linux kernel, when an audio driver ioctl handler is called, a kernel out-of-bounds write can potentially occur.
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Analysis
by VulDB Data Team • 01/16/2021
The vulnerability identified as CVE-2017-11046 represents a critical kernel-level flaw affecting multiple Android variants and Firefox OS implementations. This issue manifests within the audio driver ioctl handler component of the Linux kernel, specifically in devices utilizing the Qualcomm Snapdragon platform. The vulnerability stems from inadequate input validation within the kernel space audio subsystem, creating a pathway for malicious actors to exploit memory boundaries during ioctl operations. The affected platforms include various Android releases from Code Aurora Forum (CAF) that utilize the Linux kernel, extending to Firefox OS for MSM and QRD Android implementations. This widespread impact across multiple operating systems and hardware platforms underscores the severity and prevalence of the flaw.
The technical exploitation of this vulnerability occurs through a kernel out-of-bounds write condition that can be triggered when an audio driver ioctl handler processes malformed input parameters. This type of vulnerability falls under CWE-787, which specifically addresses out-of-bounds write conditions in software systems. When an attacker successfully exploits this flaw, they can potentially overwrite adjacent memory locations within kernel space, leading to arbitrary code execution with the highest privileges available to the kernel. The vulnerability is particularly dangerous because it operates at the kernel level, bypassing standard user-space security mechanisms and potentially allowing full system compromise. The ioctl handler's insufficient boundary checking allows for buffer overflows that can corrupt kernel memory structures, potentially leading to system crashes, privilege escalation, or persistent backdoor access.
The operational impact of CVE-2017-11046 extends far beyond simple system instability, as it provides attackers with a powerful means of gaining root-level access to affected devices. Attackers can leverage this vulnerability to execute malicious code within kernel space, effectively bypassing all standard security protections and gaining complete control over the device. This includes the ability to modify system files, install persistent malware, access sensitive user data, and potentially create covert communication channels. The vulnerability's exploitation does not require user interaction, making it particularly dangerous as it can be triggered automatically during normal audio operations. The impact is especially severe for mobile devices where audio processing is frequently utilized, providing multiple attack vectors for potential exploitation. Organizations and individuals using affected platforms face significant risk of data breaches, device compromise, and potential large-scale attacks targeting vulnerable populations.
Mitigation strategies for CVE-2017-11046 must focus on immediate patching and system hardening measures. Device manufacturers should prioritize the deployment of kernel updates containing fixes for the audio driver ioctl handler, specifically addressing the out-of-bounds write condition. System administrators should implement monitoring solutions to detect anomalous audio driver behavior that might indicate exploitation attempts. The vulnerability's classification under ATT&CK technique T1068, which covers local privilege escalation, indicates that mitigation efforts should include kernel memory protection enhancements and input validation strengthening. Additionally, organizations should consider implementing kernel module whitelisting, disabling unnecessary audio drivers, and conducting regular security audits of kernel components. The fix typically involves implementing proper bounds checking within the ioctl handler and ensuring that all input parameters are validated before processing, preventing the out-of-bounds memory access that leads to the vulnerability. Regular security assessments and staying informed about kernel security updates remain critical for maintaining system integrity against this and similar vulnerabilities.