CVE-2016-3822 in Android
Summary
by MITRE
exif.c in Matthias Wandel jhead 2.87, as used in libjhead 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 2016-08-01, allows remote attackers to execute arbitrary code or cause a denial of service (out-of-bounds access) via crafted EXIF data, aka internal bug 28868315.
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Analysis
by VulDB Data Team • 10/06/2024
The vulnerability CVE-2016-3822 represents a critical out-of-bounds memory access flaw in the jhead library's exif.c component, which was widely integrated into Android operating systems. This vulnerability specifically affects Android versions 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 2016-08-01 security patch release. The flaw arises from inadequate input validation when processing EXIF metadata within image files, creating a potential attack vector that could be exploited remotely through maliciously crafted image files. The vulnerability was internally tracked as bug 28868315, highlighting its significance within the Android security ecosystem. This issue demonstrates how image processing libraries can become entry points for sophisticated attacks, particularly when dealing with metadata parsing in mobile environments where users frequently encounter media content from untrusted sources.
The technical implementation of this vulnerability stems from improper bounds checking during the parsing of EXIF data structures within the jhead library. When the exif.c module processes malformed or specially crafted EXIF headers, it fails to validate array indices or buffer boundaries before accessing memory locations. This allows attackers to manipulate the parsing logic through carefully constructed EXIF metadata that causes the application to read or write beyond allocated memory regions. The flaw specifically manifests when the library attempts to parse image metadata fields that contain unexpected or oversized data structures, leading to memory corruption that can be leveraged for arbitrary code execution or system crashes. This type of vulnerability falls under the Common Weakness Enumeration category CWE-129, which addresses improper validation of array indices, and more specifically aligns with CWE-787, which covers out-of-bounds write operations.
The operational impact of CVE-2016-3822 extends beyond simple denial of service scenarios to encompass potential remote code execution capabilities that could compromise entire Android devices. Attackers could deliver malicious image files through various channels including email attachments, web downloads, social media platforms, or compromised websites, allowing the vulnerability to be triggered automatically when the system processes the image metadata. The exploitability is particularly concerning given that many Android applications and system services automatically parse image files without proper sandboxing or additional validation layers. When successfully exploited, this vulnerability could enable attackers to execute arbitrary code with the privileges of the affected application, potentially leading to complete device compromise, data theft, or further escalation within the Android security model. The vulnerability's presence in multiple Android versions indicates a widespread exposure that affected a significant portion of the mobile ecosystem during the affected time period.
Mitigation strategies for CVE-2016-3822 primarily focus on applying the relevant security patches released by Google as part of their Android security updates. Organizations and users should immediately update their Android devices to versions that include the patched jhead library implementation, specifically targeting Android 4.4.4, 5.0.2, 5.1.1, and the corresponding 2016-08-01 security patch releases. System administrators should implement network-level filtering to prevent the delivery of potentially malicious image files through email systems, web proxies, and content filtering solutions. Additional defensive measures include enabling automatic security updates, implementing mobile device management policies that enforce patch compliance, and conducting regular vulnerability assessments of image processing applications. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1203 (Exploitation for Client Execution) and T1068 (Exploitation for Privilege Escalation), demonstrating how metadata-based attacks can be used to establish persistent access to mobile platforms. The vulnerability also highlights the importance of input validation in image processing libraries and the need for comprehensive security testing of third-party components integrated into mobile operating systems.