CVE-2016-2506 in Android
Summary
by MITRE
DRMExtractor.cpp in 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 2016-07-01 does not validate a certain offset value, which allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted media file, aka internal bug 28175045.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 02/21/2019
The vulnerability described in CVE-2016-2506 represents a critical memory corruption flaw within the Android media processing framework that affects multiple versions of the operating system. This issue resides in the DRMExtractor.cpp component of libstagefright, which serves as a core multimedia extraction library responsible for parsing and processing digital rights management information within media files. The vulnerability specifically manifests in the mediaserver process that handles multimedia content processing, making it particularly dangerous as it operates at a system level with elevated privileges.
The technical root cause of this vulnerability stems from insufficient validation of offset values within the DRM extraction process. When processing crafted media files, the DRMExtractor.cpp component fails to properly validate certain offset parameters that indicate where specific data structures begin within the media file. This lack of validation creates a scenario where maliciously crafted media files can manipulate these offset values to point to arbitrary memory locations, potentially allowing attackers to overwrite critical memory regions or execute arbitrary code. The vulnerability falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions that can lead to memory corruption and potential code execution.
The operational impact of this vulnerability extends beyond simple code execution to encompass both remote code execution and denial of service capabilities. Attackers can leverage this flaw by delivering malicious media files through various attack vectors including email attachments, web downloads, or malicious websites that utilize the Android media processing capabilities. When a victim's device processes these crafted media files through the vulnerable mediaserver component, the memory corruption can result in arbitrary code execution with the privileges of the mediaserver process, potentially compromising the entire device. The vulnerability also enables denial of service conditions where legitimate media processing functionality is disrupted, rendering the device unable to handle normal media files.
The attack surface for this vulnerability is extensive given that Android devices frequently process media content from various sources including email, web browsers, messaging applications, and media players. The exploitation requires no user interaction beyond the automatic processing of media files, making it particularly dangerous for mobile devices that continuously process multimedia content. This vulnerability aligns with ATT&CK technique T1059.007, which involves the use of scripting languages for code execution, as the memory corruption can lead to arbitrary code execution in the context of the mediaserver process. The vulnerability also demonstrates characteristics of T1203, which involves the exploitation of software vulnerabilities for privilege escalation and system compromise.
Mitigation strategies for this vulnerability primarily involve applying the security patches released by Google as part of their regular security updates. Organizations and users should prioritize updating their Android devices to versions that include the fix for this vulnerability, specifically targeting Android 4.4.4, 5.0.2, 5.1.1, and 2016-07-01 releases or later. Additionally, network-level protections can include filtering media content at the network boundary, though this approach is less effective given that the vulnerability can be triggered through various legitimate media processing pathways. System administrators should also consider implementing mobile device management policies that enforce automatic security updates and monitor for potential exploitation attempts through anomalous media processing activities. The vulnerability highlights the importance of input validation and proper memory management practices in multimedia processing libraries, emphasizing the need for robust security controls in system-level components that handle untrusted input data.