CVE-2016-2484 in Android
Summary
by MITRE
libstagefright in mediaserver in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-06-01 does not validate OMX buffer sizes for the GSM and G711 codecs, which allows attackers to gain privileges via a crafted application, as demonstrated by obtaining Signature or SignatureOrSystem access, aka internal bug 27793163.
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Analysis
by VulDB Data Team • 01/18/2019
The vulnerability identified as CVE-2016-2484 resides within the libstagefright media processing library in Android operating systems, specifically affecting versions prior to the mentioned security patches. This flaw exists in the mediaserver component which handles multimedia processing tasks for the Android platform, making it a critical component for exploitation. The vulnerability stems from insufficient validation of OMX buffer sizes for GSM and G711 codecs, which are fundamental components used in telecommunications and multimedia processing within the Android ecosystem. The issue was classified as an internal bug with the identifier 27793163, indicating its severity and the attention it received from Google's security team.
The technical flaw manifests as a buffer overflow condition that occurs when processing malformed multimedia files containing specially crafted GSM and G711 codec data. The libstagefright library fails to properly validate the buffer sizes allocated for these specific codecs, allowing attackers to manipulate memory layout through crafted media files. This improper validation creates a scenario where attacker-controlled data can overwrite adjacent memory regions, potentially leading to arbitrary code execution within the mediaserver process. The vulnerability operates at the kernel level within the Android framework, making it particularly dangerous as it can be exploited without requiring user interaction or elevated privileges initially. According to CWE standards, this represents a classic buffer overflow vulnerability classified under CWE-121, which involves heap-based buffer overflow conditions.
The operational impact of this vulnerability extends far beyond simple media processing, as it provides attackers with the ability to escalate privileges within the Android system. Successful exploitation can result in obtaining Signature or SignatureOrSystem access levels, which grants attackers extensive control over the device's security framework. This privilege escalation capability means that attackers can install malicious applications with system-level permissions, modify system files, access sensitive user data, and potentially compromise the entire device. The vulnerability affects multiple Android versions including 4.x, 5.0.x, 5.1.x, and 6.x, making it particularly widespread across the Android platform. The exploitation timeline indicates that this vulnerability was present for several years, giving attackers ample opportunity to develop and deploy exploits against affected systems.
Mitigation strategies for CVE-2016-2484 focus primarily on applying the official Android security patches released by Google, which address the buffer validation issues in the libstagefright library. Organizations and users should prioritize immediate patch deployment across all affected Android versions, particularly those running Android 4.4.4, 5.0.2, 5.1.1, and the pre-2016-06-01 versions of Android 6.x. Additionally, network-level protections such as content filtering and media file scanning can help prevent exploitation attempts. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving privilege escalation and code execution within system processes, specifically mapping to T1068 for exploit development and T1059 for command execution. Security teams should implement monitoring for suspicious mediaserver process behavior and establish incident response procedures specifically targeting media processing exploits to ensure rapid detection and remediation of potential compromise scenarios.