CVE-2015-3842 in Android
Summary
by MITRE
Multiple heap-based buffer overflows in libeffects in the Audio Policy Service in mediaserver in Android before 5.1.1 LMY48I allow attackers to execute arbitrary code via a crafted application, aka internal bug 21953516.
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Analysis
by VulDB Data Team • 01/12/2018
The vulnerability identified as CVE-2015-3842 represents a critical heap-based buffer overflow within the libeffects library component of Android's media server system. This flaw exists in the Audio Policy Service implementation and affects Android versions prior to 5.1.1 LMY48I, making it a significant security concern for devices running older Android releases. The vulnerability stems from insufficient input validation and memory management practices within the audio processing subsystem, specifically in how the system handles effect configurations and audio policy parameters. Attackers can exploit this weakness by crafting malicious applications that trigger the buffer overflow condition during normal audio processing operations, potentially leading to arbitrary code execution with elevated privileges.
The technical nature of this vulnerability places it squarely within the CWE-121 heap-based buffer overflow category, which is classified as a memory safety error that occurs when more data is written to a buffer than it can hold. The flaw manifests in the Audio Policy Service's handling of audio effect parameters, where insufficient bounds checking allows attackers to overwrite adjacent memory locations in the heap. This type of vulnerability is particularly dangerous because it can be leveraged to execute arbitrary code within the context of the mediaserver process, which typically runs with high privileges and has access to sensitive system resources. The vulnerability's exploitation requires a crafted application that can interact with the audio policy service, making it a remote code execution threat that can be delivered through malicious applications or compromised software installations.
The operational impact of CVE-2015-3842 extends beyond simple code execution, as it provides attackers with a potential pathway to escalate privileges and gain deeper system access. The mediaserver process operates with significant system privileges, making successful exploitation particularly dangerous for device security. This vulnerability aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation' and can be categorized under T1548.001 for 'Abuse Elevation Control Mechanism'. The affected Android versions prior to 5.1.1 LMY48I would have been particularly vulnerable, as these releases did not contain the necessary memory safety mitigations and input validation improvements that were implemented in later versions. Organizations and users running affected Android versions faced substantial risk of compromise, as the vulnerability could be exploited through standard application installation processes without requiring physical device access or specialized attack vectors.
Mitigation strategies for CVE-2015-3842 primarily focus on system updates and patch management, with the most effective solution being the upgrade to Android 5.1.1 LMY48I or later versions where the vulnerability has been addressed. Security researchers and system administrators should prioritize immediate patch deployment for affected devices, as the vulnerability provides a direct path to system compromise. Additionally, application sandboxing measures and runtime monitoring can help detect and prevent exploitation attempts, though these are secondary mitigations to the primary requirement of system updates. The vulnerability highlights the importance of secure coding practices in system-level components and demonstrates the critical need for regular security assessments of core Android services. Organizations should implement comprehensive vulnerability management processes that include regular security scanning, patch deployment scheduling, and system monitoring to prevent exploitation of similar vulnerabilities in the audio processing subsystem and other system components.