CVE-2016-2495 in Android
Summary
by MITRE
SampleTable.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 2016-06-01 allows remote attackers to cause a denial of service (device hang or reboot) via a crafted file, aka internal bug 28076789.
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Analysis
by VulDB Data Team • 01/18/2019
The vulnerability identified as CVE-2016-2495 represents a critical denial of service flaw within the Android media processing framework, specifically affecting the libstagefright library component. This vulnerability exists in the SampleTable.cpp file which is part of the mediaserver process responsible for handling multimedia content processing. The flaw enables remote attackers to manipulate the system through crafted malicious media files, potentially causing device instability leading to complete system hangs or unexpected reboots. The vulnerability affects multiple Android versions including 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before the specified patch date, indicating a widespread impact across the Android ecosystem. This issue was internally tracked as bug 28076789, highlighting its significance within Google's internal vulnerability management systems.
The technical root cause of this vulnerability stems from inadequate input validation within the media parsing routines of libstagefright. When processing malformed media files, the SampleTable.cpp component fails to properly handle certain edge cases in the file structure, leading to memory corruption or infinite loops during parsing operations. The flaw specifically manifests when the mediaserver attempts to parse crafted sample table entries in multimedia containers, causing the system to enter an unrecoverable state. This type of vulnerability falls under CWE-129, which describes improper validation of array indices, and represents a classic buffer over-read scenario where the parsing logic does not adequately bounds-check array access operations. The vulnerability's exploitation requires minimal privileges as it can be triggered through remote media file delivery, making it particularly dangerous in mobile environments where users frequently encounter multimedia content from untrusted sources.
The operational impact of CVE-2016-2495 extends beyond simple service disruption to potentially compromise device availability and user experience. When exploited, the vulnerability can cause complete device hang requiring manual reboot or may trigger automatic system reboots that disrupt ongoing operations and potentially lead to data loss. In enterprise environments, this vulnerability could result in significant productivity losses as devices become temporarily unusable. The remote exploitation capability means that attackers can trigger the vulnerability through various attack vectors including malicious email attachments, web downloads, or compromised media sharing services. From an attacker perspective, this vulnerability aligns with ATT&CK technique T1499.001, which covers network denial of service attacks, and represents a common approach to device compromise through media processing vulnerabilities. The vulnerability's impact is particularly severe in mobile environments where users depend on continuous device availability for communication and productivity.
Mitigation strategies for CVE-2016-2495 require immediate system updates and patch management to address the underlying parsing flaws in libstagefright. Organizations should prioritize updating affected Android devices to versions containing the security patches released by Google, specifically targeting the mentioned version ranges that are vulnerable. System administrators should implement network-level controls to restrict access to potentially malicious media files and consider deploying mobile device management solutions that can automatically enforce security updates. The vulnerability's nature suggests that runtime protections such as address space layout randomization and stack canaries may provide additional defense-in-depth measures, though the primary mitigation remains the software patch. Network monitoring should be enhanced to detect unusual media processing activity that might indicate exploitation attempts, and users should be educated about the risks of downloading media content from untrusted sources. Security teams should also consider implementing sandboxing mechanisms around media processing components to limit the potential impact of successful exploitation attempts. The vulnerability demonstrates the critical importance of robust input validation in multimedia processing libraries and serves as a reminder of the security implications of complex media handling code in mobile operating systems.