CVE-2016-7160 in Mobile
Summary
by MITRE
A vulnerability on Samsung Mobile L(5.0/5.1) and M(6.0) devices with the Exynos7420 chipset exists because of a NULL pointer dereference in the fimg2d driver. The patch (aka "SVE-2016-6248: SystemUI Security issue") verifies if the object is null before dereferencing it.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 05/26/2019
The vulnerability identified as CVE-2016-7160 represents a critical NULL pointer dereference flaw within the fimg2d driver component of Samsung mobile devices running Android versions 5.0/5.1 and 6.0 with the Exynos7420 chipset. This issue resides in the graphics processing subsystem where the fimg2d driver handles image rendering operations for the device's display functionality. The flaw manifests when the driver attempts to access a memory location that has not been properly initialized, creating a potential pathway for system instability and security exploitation. The vulnerability specifically affects Samsung's proprietary graphics acceleration driver that interfaces with the underlying hardware to process graphical operations efficiently.
The technical nature of this vulnerability stems from inadequate input validation within the fimg2d driver's memory management routines. When processing certain graphical operations, the driver fails to properly check whether a pointer variable contains a valid memory reference before attempting to dereference it. This NULL pointer dereference condition creates an opportunity for malicious actors to trigger a system crash or potentially execute arbitrary code within the context of the graphics driver. According to CWE-476, this vulnerability maps directly to a NULL pointer dereference, which is a well-documented weakness in software development practices. The flaw operates at the kernel level within the device's graphics processing pipeline, making it particularly dangerous as it can affect system stability and potentially provide attack vectors for privilege escalation.
The operational impact of this vulnerability extends beyond simple system crashes, as it can be exploited to cause denial of service conditions that render the device unusable or enable more sophisticated attacks. When the NULL pointer dereference occurs, it typically results in a kernel panic or system reboot, disrupting normal device operations and potentially allowing attackers to gain unauthorized access to system resources. The vulnerability affects devices with the Exynos7420 chipset specifically, which was used in several Samsung Galaxy models including the Galaxy S6 and related devices. This makes the impact particularly significant given the widespread deployment of these devices in enterprise and consumer environments. The patch referenced as SVE-2016-6248 addresses this issue by implementing proper null checks before any pointer dereference operations, aligning with the fundamental principle of defensive programming that should be applied to all kernel-level components.
Security researchers have categorized this vulnerability within the context of the ATT&CK framework under the technique of privilege escalation and system compromise. The vulnerability's exploitation could potentially allow attackers to bypass security controls within the device's operating system, particularly affecting the SystemUI component which manages user interface elements and system notifications. The patch implementation demonstrates the importance of proper defensive programming practices and the necessity of validating all pointer references before dereferencing them. Organizations should consider this vulnerability when assessing their mobile device security posture, particularly in environments where Samsung devices with Exynos7420 chipsets are deployed. The vulnerability also highlights the broader challenge of securing embedded graphics drivers in mobile operating systems, where kernel-level flaws can have cascading effects on overall system security and user privacy.